haha, that sounds like a funny "problem".
Here are some thoughts:
1) Do you happen to have a Windows installer disk in a CD-ROM drive? I had to ask.
2) Do you have a CD-ROM emulator, like Daemon Tools, with an XP image loaded?
3) Do you have another partition, which perhaps has an autorun loaded to it? For example if you have a drive "E:" partition, go in look for the file "autorun". A simple test would be to just double-click the drive in My Computer, if it shows the files instead of running something, you don't have an autorun. If it does have an autorun, rename the file.
4) Have you recently ran any sort of recovery tool for Windows? Perhaps it got stuck in startup and occasionally tries to "finish" it's job?
I would ask though, is the "windows installer" you speak of, actually installing "Windows". Or trying to install something else? Cause that could be other issues. For example, if it's trying to install Office, meaning it wants to load a feature.
Does it ask you for a disk? If so, what? Does it seem like it finishes or just goes away or do you cancel it?
If that doesn't help then give us some more details on the message itself and what it says and what you do about it.
good luck