Thanks for the quick reply, but I doubt it's a virus, since I have an up to date Nod32 virus scan running, also with Spyware Blaster installed. Beyond that it's behind a corporate router/firewall and then another two routers or switches.

Getting up and running again from the NTLDR missing stuff isn't the problem really, I already fixed it, but I'm just curious how it happened and if it's a legitimate problem with the installer.