More Computer Hints and Tips

February 16, 2009

Introduction

 

This document covers in a little more detail the topics introduced at the Carefree Computer Club meeting held on 16 Feb 2009.  The principal subjects included:

 

·         Why do some of my files have blue color wordings?

 

Types of DVD

 

This is an overview of the Recordable DVD formats for Set Top DVD Recorders and Computer DVD Burners.  There are five recordable versions of DVD:

 

 

DVD-R and DVD+R can record data once, like CD-R, whereas DVD-RAM, DVD-RW, and DVD+RW can be rewritten thousands of times, like CD-RW. DVD-RAM is a removable storage device for computers and video recording. It has become widely used in DVD video recorders because of the flexibility it provides in editing a recording. The other two recordable format types (DVD-R/RW and DVD+R/RW) are essentially in competition with each other. There are many claims that one or the other format is better, but they are actually very similar. Many manufacturers now offer Set Top DVD Recorders and DVD Burners that record in both "dash" and "plus" format. Below is a brief look at each format.

 

DVD-R

 

A write-once format that is compatible with many existing DVD Players, recorders and DVD-ROM drives.  Can only be used in DVD recorders and burners that support DVD-R recording or multi-format recording (drives that record "plus" or "dash").  Holds 4.7 GB of data or video.  Typically, it can hold 2 hours of MPEG-2 video on standard (SP) speed setting.

 

DVD-RW

 

DVD-RW is the re-writable version of DVD-R. It allows for approximately 1,000 re-writes before it is used up. In general, DVD-RW discs are slightly less compatible than DVD-R. Can only be used in DVD recorders and burners that support DVD-RW recording or multi-format recording (drives that record "plus" or "dash").  Also holds 4.7 GB of data or video.

 

DVD+R

 

Another write-once recordable DVD format developed separate from DVD-R. These discs are basically the same as DVD-R discs. They hold 4.7GB of data or video and are compatible with most DVD players and DVD-ROM drives. They can only be used in DVD recorders and burners that support DVD+R or multi-format recorders.

 

DVD+RW

 

This is the re-writable version of DVD+R. It can record approximately 1,000 times. They also hold 4.7GB of data or video and must be used in DVD+RW compatible recorders and burners or multi-format recorders.

 

DVD-RAM

 

DVD-RAM comes in two varieties and storage capacities. These discs come in both cartridge and non-cartridge varieties and come single-sided or double-sided. Offered by only a few manufacturers (Panasonic, Toshiba and a few other minor ones), DVD-RAM is useful if used like a hard drive.  Because it supports an incredible 100,000 re-writes, you can use the disc to record TV shows, view them and then re-write over them many times.  Single sided discs hold 4.7 GB, double-sided 9.4 GB, allowing for longer recording times.  DVD-RAM is the least compatible of the 5 recording formats, and is typically used for recording and playback in the same Set Top DVD Recorder.

 

Final Thoughts: when choosing a format to use, keep in mind that DVD-R/RW won't record in a DVD+R/RW recorder or burner, and vice-versa. This is not an issue when using a Multi-Format recorder or burner, and most DVD players and DVD-ROM drives will read either format.

ActiveX Controls

ActiveX is the mechanism by which Internet Explorer (IE) loads other applications in the browser. Through ActiveX, IE loads Windows Media Player, Flash, QuickTime, and other applications that can read files embedded in web pages. ActiveX controls are activated when you click an item such as a .WMV file on a web page to download it for display in your Internet Explorer browser window.

As a Microsoft product, ActiveX was specifically designed to work with Windows systems. Microsoft does not support ActiveX on other operating systems such as Mac or Linux.

Firefox and other browsers that work on multiple operating systems use the Netscape Plugin Application Programming Interface (NPAPI) system. NPAPI performs functions similar to those of ActiveX.

 

File Extensions

There are some basic things you need to understand about file extensions. First, you need to understand what an extension is.  Second, you need to understand that it's possible your computer is not showing you file extensions, and what to do about that.

What is an Extension?

Disk files have to be identified so the operating system can address them. These filenames have specific rules.

The basic form of a filename is:

rootname.ext

The first part of the name to the left of the period is called the root name. The second part to the right of the period is the extension. It is often, but not necessarily, three characters long.  The period is used between the root name and extension and must be present if there is an extension. The root name under Windows may contain multiple periods. Only the last one is the divider between the root name and extension.

In general, Windows operating systems traditionally the extension on a file name has been used to identify a program the file is associated with (e.g., the .EXE extension almost always represents an executable program; the .DOC extension mostly represents a Microsoft Word document file, etc.).

Because there are only so many three-letter extensions, any given extension might be linked to more than one program.  Extensions can be spoofed. Some Word macro viruses create a Word file in template format and save it with a .DOC extension. Since Word generally ignores extensions and looks at the format of the file these would open as templates, execute, and spread the virus.

If you use symbols (things other than A-Z, 0-9) in the name of a file, the symbols may cause problems if you try to transfer that file to a CD disc.  CD naming conventions are often more strict than Windows naming conventions.

Different operation systems can present problems when moving between them. For example, Windows is case insensitive. PSPIMAGE, PSPImage, or PspImage are all the same to Windows. However, under UNIX all three would be different files as UNIX file names are case sensitive.

It becomes even more complicated when Windows starts to recognize files by format and not file extension.

For a variety of reasons you should make certain that your computer always shows file extensions. Under Windows you can set the system to hide extensions. This is dangerous as some malicious programs will send executable files with a double extension in order to try to fool you into thinking the file is not malicious. For example, if you receive the file BADPROGRAM.TXT.VBS and have extensions turned off you would only see BADPROGRAM.TXT and think that the file is a simple text file.  If you clicked on it you would execute a script that could do anything.

Here are the instructions to make most extensions display:

Making Extensions Display - Windows XP

In Windows XP open any folder (view the contents of any folder in My Documents).  Click on the icon in the Navigation Bar that gives different view options.  Choose Details, then...

Select Tools > Folder Options

Select the View Tab, and then scroll down to the entry that says, “Hide extensions for known file types” and makes certain it is not checked.

Click on the Apply To All Folders button and then close the window.

With this move you will now see extensions in file directory windows and other Microsoft programs like Outlook will pick up the option.

Set File Extension Display XP

Making Extensions Display - Windows Vista

The procedure for making file extensions show up in Vista is similar to that for Windows XP.

Once you open any Windows Explorer window (e.g., Documents or any other) there are three basic steps:

1) Click on the Organize button.

2) Select the Folder and Search Options menu item.

3) Take the View Tab and scroll down the list to the Hide extensions for known file types item and make sure it is not checked.

 

Vista Show File Extensions

Making Extensions Display - Windows 98

In Windows 98 double click to open My Computer and then select View > Folder Options. Then...

Select the View Tab, then scroll down to the entry that says "Hide file extensions for known file types" and make certain it is not checked.

Click OK and then close the My Computer window.

With this move you will now see extensions in file directory windows and other Microsoft programs like Outlook will pick up the option.

Show File Extensions Win98

Special Cases

When you send and receive attachments with GMail, they are auto-scanned for viruses.  If Gmail thinks your mail has viruses, it will attempt to clean the file or remove it.  If it detects a virus and can't remove it, you won't be able to download it.

Thanks to the new GMail Anti Virus Scanner, you cannot send or receive emails containing files with exe, dll, ocx, com or bat extensions even if they are sent in a zipped (.zip, .tar, .tgz, .taz, .z, .gz) format (The .rar format is still allowed)

When you try to email a file with the above extensions, GMail may upload the entire file but give you this alert:

This is an executable file. For security reasons, Gmail does not allow you to send this type of file.

This is such a poor solution.  GMail Virus Scanner didn't scan the attachment; it just blocked it since it was an exe file. Why is Google calling it an AntiVirus scanner when it is merely blocking attachments of certain types like .exe? Yahoo! webmail too has an anti-virus component but it accepts .exe files since the Yahoo anti-virus scans even exe files and cleans them if found infected.

Google has no plans to make the "limited" antivirus feature optional, nor does it plan to stop blocking executables. Yahoo! Mail uses Symantec software to scan for viruses. Hotmail licenses its technology from Trend Micro. Google isn’t saying which vendor is providing the antivirus technology.

Since you cannot turn off GMail AntiVirus Scanning, you can use these GMail hacks to send program files (exe), virus samples and other blocked formats with GMail:

Rename the file: change the file extension to fool the GMail scanner.  The new attachment could contain instructions making it easier for the recipient to derive the actual attachment type. For instance,

Rename Adobe-Reader.exe to Adobe-Reader.exe.removeme

If you have lot of exe files to send, put them in a zip file and change the extension of the zip file as mentioned in the previous step. Remember that GMail denies zip attachments that contain exe files.

Sending Virus infected files with GMail: Yes, it is against the GMail Terms Of Service to send viruses in email but, occasionally, we need to mail an infected file for reporting purposes to an antivirus vendor.   The Symantec Security Response center encourages users to submit virus samples for analysis.

Management of the folders in My Documents

Your operating system comes with a set of pre-named folders contained in the main folder called My Documents.  The only place that you should be saving your data is in My Documents.  It is up to you to manage any saved data so that you can easily find it at a later date.  For instance, if you collect music, there is a folder called My Music, but you will probably want to group your music by artist or composer.  You will want to create individual folders inside the My Music folder to contain different types of music.  The same goes for photos, which should be saved in the My Pictures folder.  Sub-folders should be created to contain photos that all relate to a specific subject.  You will need more sub-folders in My Documents to accommodate text files, e.g. tax papers, medical information, saved bills.

How do you create these folders?  As usual in Windows, there are several ways to do the same task.  Here’s one way:

Try to avoid keeping data files (music, text or pictures) in folders on the Desktop of your computer.  That space should strictly be used for shortcuts to frequently used programs.  All data is best kept somewhere in My Documents.

 

Why do some of my files have blue color wordings?

 

When you use the Explore function, you may find that some files have blue wordings instead of the normal black. If you check the properties of your files, the compress attributes will be ticked.  Files with blue filenames means that they are compressed in order to save disk space. This option might have been activated knowingly or accidentally when running the disk maintenance.
It is a feature of XP to compress unused files.  If you want to undo that you can:

Click on My Computer>Tools>Folder Options>View tab> Advanced Settings>Uncheck "Show encrypted or compressed NTFS files in color".  It’s almost the last option.

 

Program updates

To keep your computer running as securely and efficiently as possible, Microsoft and other program distributors send out frequent updates.  When you are connected to the Internet, if you receive a message telling you that updates are available for certain programs installed on your computer, you have the option of downloading and installing the updates or declining them.  The first thing to decide is, are you sure that the update is a normal process or something new, which you may have to pay for!  Decline any updates for software that has hitherto been freely updated (AVG and ZoneAlarm do this frequently, while not making it clear that you can continue with the free version indefinitely). 

You can trust Windows to go ahead and do updates, but you may not like the way your computer works after the update.  For instance, Windows Media Player may update to a new version that you don’t like.  In that case, go to your System Restore and restore your computer to just before the update.  Windows updates always create a restore point just for this reason.

What kind of wireless router should you buy?

What’s the difference between wireless N and G type routers and which one is better?  I have come to the conclusion that G routers are good for covering small areas, give maximum speed of 54 Mbps, and are comparatively cheaper than N routers.  N routers cover greater areas and offer higher speed than the G category.
 
Wireless G is the current national standard we are using for wireless. It is rated at a maximum speed of 54 Mbps with a radius range of approximately 75 feet. Please keep in mind that both numbers are based on a clear line of sight and every wall, floor and piece of furniture in your house will affect these numbers.

Wireless N is the new standard that will soon replace G. It is based on MIMO technology (multiple input, multiple output) which is why most N devices have either larger or multiple antennas. You will be hard-pressed to get actual speed and distance claims from the manufacturers as they seem fluctuate, but in theory it should be up to 200 Mbps and up to 150 feet.

A couple of tips to remember:

1. As N is not yet standardized, each manufacturer is utilizing his own technologies, which may not be compatible with each other or with the finalized standard.

2. To date we do not have any PC notebooks that are shipping with wireless N cards built in.  As such a notebook or USB adapter would need to be purchased with the router to achieve the expected performance.

3. Most N products are A, B & G compatible

The N protocol has a longer range than either of its own predecessors. B and G had an effective, unobstructed range of about 100 feet. N supposedly has a range of nearly 700 feet, though in practice you may not see anywhere near that. Most N routers also have two aerials, allowing them to transmit a dual signal, which can give much faster reception rates on appropriate network cards.

All N routers have backwards compatibility with B and G so existing network cards and laptops will work fine with them, but if you have range-boosted and speed-boosted N equipment you will see a noticeable difference.

Error Reporting

If a program has to close unexpectedly, a message will be displayed informing you of the error.  If Error Reporting is enabled, you will have the option of sending or not sending the report of your problem to Microsoft.  If this annoys you, or you simply do not wish to send error reports, you can disable the function quite easily.

To enable or disable error reporting:

·         Click Start, click Control Panel, and then double-click System.

·         On the Advanced tab, click Error Reporting.

·         Click Disable error reporting or Enable error reporting.

If you disable error reporting, you can still have Windows notify you when an error occurs.  To do so, select the ‘But notify me when critical errors occur’ check box.

To enable operating system error reporting, select the Windows operating system check box.

To enable program error reporting, such as Microsoft Word, select the Programs check box.

 

That’s all for this time.  Remember to keep your computer anti-virus program up to date, and scan frequently!

Dave Clark