Disappearing-Reappearing Desktop Icons

Ive just recently started to have trouble with my machine. The stats are:

OS: Win XP Pro SP2
HDD: 500Gb SATA
RAM: 2Gb
CPU: Phenom 9850 Quad Core 2.5GHz
GPU: ATi Radeon 3870

My problem is when i boot up my computer, it goes to the Welcome Screen and takes longer to load than normal, then when the Desktop appears, it is blank with no icons, and the programs in the bottom right where the clock is are gone. The only things there are the blank desktop, the Start Menu, and the clock. I didnt know what to do, but i waited for a minute and the Icons and Tasks all appeared and everything was normal.

When the Icons came back, i received first an error message about Data Execution Prevention on 'Flashy.exe' (I know this is a virus or something but Ad-Aware wont pick it up and delete it).

I cancel that and then i get a message from the Catalyst Control Center saying i dont have administrative privliges to change the settings in it, but i havent changed anything relating to the video card, software or hardware, since i put it in/installed it 3 months ago and have had no problems.

Also, I looked at the Task Manager and a Task called wmisys.exe keeps starting then stopping and never stops. It will appear on the Task Menu then disappear, then come back again. When it does this the CPU also spikes to 11% usage then drops to 0%.

Any help would be great, thank you