Thanks for your time,

im afraid there wasn't a lot more i could say. It locks up totally random. Sometimes when im playing games sometimes surfing sometimes doing nothing. It locked up trying to write this twice. . .

anyway i did as you suggested. ran the system file checker. it did its thing and fixed some files but said it couldn't fix them all?
To be honest the log file went well over my head and the site you suggested didnt help much.

as im writing this, for the third time, i have disabled all of vistas eye candy, eg aero after thinking that might be the problem and it hasn't frozen for 30 mins (crosses fingers)

so any other ideas? im in your debt

thanks for your time