OTHER USER virus

Spent the last 3 months trying to recoup and recover from a virus. I won't bore you with recounting everything that's been done already.. though it is a lot!
After having a tech look at it, I've decided to restore/reformat. There is a problem.

I don't have installation disc's. So, I want to use Vista's Recovery tools. One of the lasting effects of the original infection is this: When I boot into any Repair mode, I get a log-on screen that consists of a single windows log-on icon. The icon is titled, OTHER USER. When I click on OTHER USER, I'm prompted for a user name and password. Of course, I have no clue as to what that might be. There is no other choice, and no way to exit except to power off my pc.

First, there is no "other user". This is a virus. It is a false "log-on" that merely prevents me from using any repair tools, including recovery. So, no rearranging, disabling, passwording, creating new user acct methods work.

I made a boot disk with repair tools, but have been unable to make it work. For some reason, it does not recognize my Product ID. When I attempt to install without that (which is an option), I get an error message citing a "missing" file.

Google has many many hits for this "other user" virus... but, no solutions.

Do you have any? Pleeeeeeeeeeeeeeeeease ??

Here is the solution
Once you get a serious virus, there is not way to be 100% certain that its removed unless you format. Most virus are not serious enough or cause enough problems to warrant such a solution.
What you should do to completely remove it and to get working again is to buy, for cost, or borrow a Vista DVD, then with the DVD format. Everything will be gone, including any virus remnants. Then just reintall. You can get a Vista reinstall DVD from your computer manufactuer for about $25.00