Win ME install problems

I have had a dell dimension 8100 with windows me for about 5 years. 40 HD and 384 memory, hard drive 1 year old, video card 2 years old and memory 1 year old. Run several anti-spyware programs: Avast, Adaware, Spybot, SpywareBlaster and Spygate with no virus and some tracking found once in awhile. I would do checks every couple of days. For last month computer running slow and was looking into getting more memory when started having major problems last week. Started freezing up and very slow after windows update. Decided to delete some programs I do not use: windows help (they are a joke), children's educational games, old programs I had updated, etc. After doing this, computer crashed and went in to safe mode. I attempted system restore but no restore dates would work, tried scan disk but it would not work, windows me start up disk with no change, etc. and finally decided to reformat hard drive and reinstall program. Did show some corrupted files and these were corrected.

This went well and I would add a few programs and run the computer for awhile, do a defrag and then do a restore date. Started with video card and drivers then work suite and printer next internet and antispyware programs. After the last two, I began having problems again with the programs freezing and would not close even with ctl-alt-del, dial up suddenly starting, internet disconnecting without warning or suddenly the computer shutting down. Attempted to use system restore and it would not restore to any of my restore dates. Attempted to do scandisk but it kept saying programs running in background. No programs shown in alt-del-ctl and had set up on selective start-up. Did a drive scan online which showed no probems and diskscan showed some corrupted files but did not show me which one. Did a DOS scan disk which showed no problems. checked device manager and it showed unknown device.

I am at a lost where to go from here. Do another reformat and reinstall? If I do, how can I figure out what is causing corruption to my files. what is the best process for loading programs back onto the computer? I hate windows updates, have had nothing but problems when I use them, are there ones I do not need to download? Is there a way to fix corrupted files or at least find out which ones are corrupted? I own a home-based business and this is really using up lots of my time formating, installing operating system then programs, documents, etc. only to have to do it over again. Have thought about upgrading to XP but have so many programs for win me or earlier that would be expensive to replace for XP and from what I have read on forums and revies, it is much better than ME. 2000 Professional has been recommended.