fixmbr

and that will remove GRUB from your system.

◙ About Nero8:

Use CCleaner and delete all entries related to Nero. I think your installation file may be corrupted. I faced this problem as well, on an older installation of XP. I downloaded Nero7 an that worked. Later when I reinstalled windows (64-bit) I tried to run Nero8 and again it did the same thing, so I just got a new version. (if your is a fresh.. copy.. then I suggest.. copying it from another source).

◙ Hmm... I think your explorer is acting up. Happens during a faulty installation (of windows). The quickest way I would recommend is reinstall Windows over your System drive (make backups) this will get rid of all the trojans and viruses you may have been given as free gifts from the "Update" sites.
Run a good virus + trojan cleaner /scanner to establish if any unwanted creeps are there or no.

◙ About your drivers:

Have you tried uninstalling the drivers from the safe mode? normal mode won't remove them (as it makes a backup in real time). I faced a similar problem with onboard audio of a mobo.. this method worked.
Uninstall in Safe mode and then reinstall in normal mode.

◙ About your SoundCard:

Can you post a pic of you soundcard?