Should be C:\boot.ini. It's hidden and read-only, so go to a C:\ prompt and type (without the quotes of course) "attrib -s -h -r c:\boot.ini". Then just edit it with notepad or some other text editor (*TEXT* editor, not wordpad or MS Word, etc). Inside you'll see an Operating Systems section and under that should be 2 lines that start with multi(0)rdisk.... and at the end of the lines is some text in quotations - that text is what you see when you boot.
Add something unique inside of each quotation - like #1 at the end of one line and #2 at the end of the other. Save and exit and verify which one is bogus, then delete the entire line from the boot.ini ("attrib +h +s +r c:\boot.ini" when you're done).
Google "editing the boot.ini" if you need more info.
Good luck.