I recently started getting what look like little bar-codes all over my desktop and around text and cursors. The quantity grows over time and clears with a system reboot. My vid-card is an ATI Radeon 9500 with up to date drivers on a Win7 home built PC. Any ideas on the source of these lines?
These are called artifacts. They occur when the GPU is malfunctioning. My suggestion would be to check temperatures because it could be overheating. If it's not overheating then it is probably just dying. If it's overheating than you might have a stuck fan or you fan speeds aren't high enough.