I would appreciate any thoughts or advice on the following: My keyboard and mouse have stopped working for a period of 1-2 days on two occasions now several months apart. PC: Dell Dimension E520 Keyboard/Mouse: Microsoft Wireless Keyboard 800 and Wireless Mouse 1000 (combo) using a single wireless USB receiver. OS: Windows XP Attempts to resolve: 1. Batteries: fresh both times. Changed to new batteries. Not a battery problem. Mouse tracking light is active. 2. Windows platform problem: during start up, would not respond to F2 or F8 commands 3. USB hub: I tried moving the wireless receiver to USB ports in the front and back of computer with no resolution. Items that charge from the USB continue to receive a charge. However, external drives (like my phone) do not autoplay or prompt me to choose what to do with them like usual, as if the computer don't know they are plugged in. 4. Inspecting the tower: I remove the access panel on the side for a full view. I gently press on each component to ensure they are not loose. Each time, the problem resolves after I take the tower to the garage and blow it out with my air compressor. The first time is was fairly dusty as I had not done that in a while. Most recently (today), it was hardly dusty at all since I has this problem not too long ago. Still, after powering it back up and plugging in the wireless receiver to the front USB port, it recognized the device and now it works fine. It also recognizes the receiver in the back USB ports as well. So, blowing it out has worked 2 out of 2 times. Someone at Best Buy said it might be a PCI card problem. Any thoughts? Any way to confirm that?