Going through your log files; if you are willing to do a restore,

RP1113: 5/10/2010 10:47:38 AM - System Checkpoint ~this one, or 5/9, any restore point that you have prior to installing Advanced System Optimizer..
RP1114: 5/10/2010 1:01:22 PM - Advanced System Optimizer

Most of the work to tidy up your pc will be un-done, but it's repeatable and you will have a better understanding of the process via repetitive practice.

You mentioned that you have 4x1GB..

Windows xp can't actually use 4GB without special configurations done by the end users "windows tweaking" and some motherboards are less than stable with all 4 memory slots occupied..

I know this sounds counter productive, but windows generally only uses 3072 MB of physical ram, as will be shown in the system properties even with 4GB installed..

Did you buy the extra ram to do a certain task on the PC?

Try pulling out ONE stick of memory, leaving only three installed...

If you have dual channel DDR2 memory, then you will want to pull two sticks, so that Dual channel is still enabled, to hopefully "increase performance".. This will only leave you with 2GB max system ram installed and 3027MB fixed pagefile....

You will have this limmit on the amount of things that you can do on your computer, spreadsheets may not load if they are "HUGE" but pretty much everthing else should still work, without a noticeable decrease in "performance" and in some instances, the computer is actually faster with less ram, 1-2GB installed with One stick, or two paired in dual channel. Due to the more stable memory/databus..