windows loading problem

td2000

After days of troubleshooting and a few headaches I decided to go after some outside help. What Im working with: emachine T2482 AMD Athlon X2400+ 2.00GHZ, 2 cards of: 128mb and 512mb RAM the 512 being the newly installed. Im running Win XP Home, Zone Alarm, Up to date Virus Protection, Windows is up to date, Bios is recognizing the new memory, memtest86 and microsoft memory test have come back good, drivers are up to date and I regularly run ccleaner, Reg scrub, Spybot, spyhunter, and virus scans. Everything always comes back clean. Okay with that said heres my issue. A few weeks ago I noticed when I move files to a different area it would include a thumbs.db file, this is a file that goes with my webpage and has nothing to do with Im working on, or it seems its making its own files or something especialy in "my pictures". Okay I recently added the 512 mb of RAM and when I open win explorer my icons and thumbnails are comming up scrambled small and pixelized so to speak so I refresh and there fine untill I try and scroll down and it freezes for 30-40 secs, wont do anything. After scrolling the new pictures in view are the same way (screwd up) until I refresh. God forbid I try and max the page, then Im stuck with a max page and the smaller page stuck inside till it catches up. Now all said my programs run fine, internet runs fine and I have a new bar on the left of my screen in windows with a list of options to choose from that I never had before. I think this is an option Ive accidently turned on. Anyway Ive rulled out the memory being the problem because I've swapped cards, tried running just the new one, just the old one and every combo yields the same result. The memory was from Crucial so I know its compatible and all memory tests come back good. I know this is long and im sory for that, Im just trying to provide as much info as possible. Oh Ive done the clean disk and defrag. I would greatly appretiate any thoughts or ideas on this situation. td2000