I don`t have BF1942 so I don`t know, it could be the settings stayed behind when you removed the game, with games often the un-installer leaves the game folder behind with a settings file in it and any saved games you had, maybe if you remove the game again, then find the folder in "program files" and remove that and then re-install (but save any old games to another location 1st), other than that you could try something like 3dmark, but since other stuff runs at full speed it seems your install is ok, so maybe the crash broke something?, you could try system restoring back to a while back, other than that I am not sure, as for altering the drivers, the cards drivers should be in add/remove programs, failing that just try to install the Nvidia driver over the old one, I have done that once or twice accidentaly and it doesn`t seem to hurt anything (although removing the old driver and rebooting is recomended by Nvidia...and they should know better than me).
Windows: 32 bit extension/graphical shell for a 16bit patch to an 8bit OS originally coded for a 4bit CPU, written by a 2bit company that can't stand 1bit of competition, now available in 64bits.