I have a Dell 531S with 3Gb memory I bought about 2 years ago. A few weeks ago I started getting latency on basic desktop functionality. The system continued to degrade to the point where various subsystems would conflict with each other and nothing would be happening. I ran about 15 different virus/rootkit analysis and found nothing. I then overlaid the OS on the existing file set. The problem continued and I just reformatted the drive and do a fresh install on the same drive (C. I ran a memtest and it does not appear to have any issues with the memory sticks. Even after the fresh install I still get latency and the desktop hangs up...mainly when searching IO devices (external drives) and the internet. Any suggestions on what else I might look at?