To disable Messenger in WIN XP, do the following:
1. Got Start | Control Panel | Performance and Maintenance | Administrative Tools.
2. Double-click Services
3. In the Services panel scroll down and select Messenger.
4. Right-click and select Stop to turn off Messenger.
5. Right-click again and select properties.
6. In the Startup Type drop-down list, select Diasabled.
7. Click on apply and then OK, the service should now show disabled.
On the rest of your message, wow, not sure where to begin. I use Norton Anti-Virus and I keep the definitions up to date and have never had a virus that the software did not catch. So not sure what your problem is. People here in the forums will have their own opinion on what is the best anti-virus software, but Norton is adequate if kept updated.
Windows XP is a perfectly good OS. I run WIN XP PRO on my gaming computer and WIN XP Home on my general use computer. Both work fine, but neither Microsoft product is perfect. Going with Linux would only bring you other problems, like compatibility issues with your games, etc. Go to
http://www.tweaktown.com and print out their Windowns XP Tweaking newsletter and follow their suggestions to tweak XP to be a little better gaming OS etc.
I would think these days, to have a good gaming computer, you are going to need to upgrade your computer. Whether you upgrade your existing PC, or buy or build a new one depends on how much you can spend. Minimum these days is all in the eyes of the beholder, but here are my suggestions.
WIN XP PRO (Home if you already have that license)
AMD Athlon XP 2700+ FSB 333 or Intel Pentium 4 2.4
A MOBO that supports that chip and PC2700 or PC3200 memory. Two 512MB 184 pin DIMM DDR PC3200 from Corsair or Crucial is best. On board SATA so you can run two 80 GB SATA HDD in RAID 0, or one 120 GB ATA133 HDD works fine. Spend your money on the video card. I have an ATI Radeon 9800 PRO and its super, but you can get their middle of the road 9600 that supports DirectX 9.1 for $150.00. Get 128MB DDR with AGP 8X minimum. Look at the thread on the 9600 Pro now in the forums. That 9600XT looks like a killer board. When looking at MOBO's spend a $150.00 and get a mobo with all the latest bell and whistles. Even if you do not plan on using all of them now, like SATA, at least you will not be upgrading again in six months.
Good luck Killer.............Mo!