J'avais eu ce problème il y a plus d'un an (pour moi, c'était le backup de Windows, cf ci-dessous, mais il y a d'autres causes)
Vu dans FAQ Geforce
Question : Windows locks up before it finishes loading, and a thin green line may appear across the top of the screen. How can I fix it?
1/ This may be caused by the Backup utility supplied with Windows 9x/ME attempting to detect new tape devices on boot. You can fix it by deleting the files drvwppqt.vxd and drvwq117.vxd in the Windows\System\Iosubsys directory. If this helps, then search for the string 'TAPEDETECT' in your registry and delete any entries that exist. If you find this causes your tape drive to stop working, you'll have to reinstall Microsoft Backup. You can also simply uninstall Microsoft Backup if you don't use it.
2/ Try updating the motherboard's BIOS. In particular on some Gigabyte boards based on the VIA KT133 chipset this may fix the problem. See the following page for more information:
http://www.giga-byte.com/faq/quest [...] _kt133.htm
This may also fix the problem on ASUS A7V motherboards - upgrade the BIOS to version 1004C or later.
3/ You may find that on motherboards that are only AGP 1.0 compliant you may be able to fix this problem by putting insulating tape over the last pair of contacts on the AGP connector on the GeForce card (the contact furthest from the monitor port, on both sides). This has been tested on the Chaintech 6BTM motherboard. You may find that once you have done this once you will be able to take the tape back off (even if the tape didn't seem to have any effect).
4/ Try disabling the Windows startup sound.
5/ Make sure that VSYNC is enabled in the NVIDIA control panel.
6/ If you have IomegaWare installed, try uninstalling it. If this fixes the problem, just use Iomega Guest.
Source :
http://www.geforcefaq.com/faq.cgi# [...] :startlock