Miscellaneous stuff

What Windows Version do I have?

Click Start, Select Run, now type in: WINVER
Press Enter
or
Press Windows key + Pause Break key

To find out if you have a 32 bit system (x86) -
Click Start, Select Run, now type in: msinfo32

For Vista

Click Start button, click Control Panel, click System and Maintenance and finally click Welcome Center.
The edition of Windows Vista you are running is displayed with your computer details near the top of the window.

Lost your Product Code Key

If Windows XP is still installed on the computer:

ProduKey - Recover lost product key (CD-Key) of Windows/MS-Office
http://nirsoft.net/utils/product_cd_key_viewer.html

Magical Jelly Bean Keyfinder
http://www.magicaljellybean.com/keyfinder.shtml

If you purchased WinXP retail, the Product Key is on an orange label on the back of the package. If you don’t have the package, contact Microsoft:
http://support.microsoft.com/kb/295539

How to Replace Lost, Broken, or Missing Microsoft Software or Hardware
http://support.microsoft.com/kb/326246

If you have an OEM version of WinXP, the Product Key sticker should have been placed on the computer tower by the retailer. Note, Microsoft will be unable to assist you with an OEM version.

Setup Boot Disks

Obtaining Windows XP Setup Boot Disks
http://support.microsoft.com/kb/310994

Startup Programs

All about disabling programs at startup
http://www.pacs-portal.co.uk/startup_content.php
http://www.answersthatwork.com/Tasklist_pages/tasklist.htm

Also see:
http://www.microsoft.com/technet/sysinternals/utilities/Autoruns.mspx

Security -

Unexplained computer behavior may be caused by third-party software
http://support.microsoft.com/kb/827315

Microsoft NEVER sends Email with attachments.
http://www.microsoft.com/technet/security/news/patch_hoax.mspx

Protect your computer
http://www.microsoft.com/protect/computer/default.mspx

Windows Defender from Microsoft
http://www.microsoft.com/athome/security/spyware/software/default.mspx

Virus Scanning Recommendations - preventing corruption of the softwaredistribution\datastore folder

Virus scanning recommendations for computers that are running Windows Server 2003, Windows 2000, or Windows XP
http://support.microsoft.com/kb/822158

Free software

Office Suite - Compatible with all other major office suites, the product is free to download, use, and distribute.
http://www.openoffice.org/
PDF Creator – PrimoPDF
http://www.primopdf.com/
Paint.NET is free image editing and photo manipulation software designed to be used on computers that run Windows. It supports layers, unlimited undo, special effects, and a wide variety of useful and powerful tools.
http://www.getpaint.net/index.html
GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages.
http://gimp.org/
DeepBurner Free
http://www.deepburner.com/
ImgBurn (burn ISO images)
http://www.imgburn.com/
Final Burner Free
http://www.protectedsoft.com/descr_fb.php
BWGBurn
http://sourceforge.net/projects/bwgburn
BurnAware FREE Edition
http://www.burnaware.com/
CDBurnerXP Pro is a free CD/DVD burning solution.
With this software you can burn CD-R, CD-RW DVD+R/RW DVD-R/RW discs.
http://www.cdburnerxp.se/features.php
The Free, Cross-Platform Sound Editor
http://audacity.sourceforge.net/
An Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format
http://www.inkscape.org/

I've provided a list of products that are free for convenience. It's up to you to decide whether or not they are of interest to you or not.

TaurArian