Did you install on the primary drive or some other drive or partition?
That file MUST reside on the primary drive: C:\ or multi(0)disk(0)rdisk(0)partition(0) if you need low level addressing.
If the OS is NOT on the primary drive, the file could be present on the drive holding the OS. In that case, copy or move it to the primary drive.
A Linux Live CD can be used for that.
If you can't find that file anywhere, you'll beed to reinstall your OS, again, as there was some problem during the installation process and that file, and maybe others, where not properly writen to the drive.
Electro
July 2011