sounds like you mite have to reformat your computer,,,,,or find a new hard drive,,or 3d card<~~i know a few people who have had more trouble with geforce 3,,than a geforce 2,,lol,,,and game shuttering and loss of frame rates,,can be your hard drive taking a dive,,,my cousin was having about the same problem,,and thought it was 3d card,,,but it turned out being a hard drive going under,,even know all the scan disk and defrag said it was still good,,,it wasnt,,,after multiple reformats,,,we gave up,,and got a new hard drive for it,,,,and it fixed everything,,no more shutters or slow frame rates