Thanks for your reply.
I found out how to make the laptop boot from USB (by changing one BIOS setting that wasn't obvious) but that turned out to be a dead end. I made a recovery DVD though and that gets me to the command line.
Bottom line, the Corsair driver is preventing the laptop from booting, and I can't get rid of it. A simple delete doesn't work of course, since it's restored from the driver store on reboot, but even deleting the OEM##.INF files using pnputil has no permanent effect: the INF files come back on reboot, too...
edit: starting to suspect the INFs are being restored from another partition :(