Hi, I am not sure how to describe the issue so all my googling has been in vain, I hope you can help. I am not even sure which section to post, I assume it's software-related but maybe it's not. I am running Win 7 with Asus p5K motherboard 4GB RAM NVIDIA GeForce 8500 GT. Since yesterday (no new installs) when playing videos occasionally red or/and short squiggly lines appear for a few frames - kind of flash-like - and disappear. They return in different parts of the frame at irregular intervals. Could not make screens as in KMPlayer scrolling between single frames the lines appear to be inter frame (appear only on the scroll between two frames but in neither of the two). I am also noticing a similar event, this time covering all the monitor which much longer lines, at boot. Specifically, after I input my password. So far I have ascertained that: 1. it's not a problem with the files themselves - I am having the issue also with older files which I have already viewed without pronlems 2. it's not format related - I am having it with all the formats I tested: .avi, .mpg, .mp4, .flv 3. it's not player related: it's occurring with KMPlayer, Media Player Classic - Home Cinema and VLC portable which I just downloaded for a third option I have attempted the following so far, without having any results: 1. rebooting 2. uninstalling all codecs and reinstalling the latest K-Lite Codec Pack 3. updating the NVIDIA drivers 4. checking device manager As I mentioned, I have been unable to google for the problem, as all description I have come up with appear to produce unrelated hits.