If you've done a recent virus scan and it caught something, this could be a randomly-named leftover. The fact that it can’t be found might actually be a good thing, although a nuisance. I take it you just click the OK button and your system runs right after that?
If so, you may be able to get rid of the useless message by going into msconfig and keeping the file from trying to start up. Here's how:
1. Click on the Start->Run menu item.
2. In the Run text box, type in msconfig, then press Enter.
3. In MsConfig, click the Startup tab.
4. See if there's an entry for that filename. If there is, clear the checkbox next to its name. Note: Windows Vista even has a column that can show the entire command the program was called up with. To display it, click View->Select Columns and check the Command Line checkbox, then click OK.
5. Click OK.
6. Accept the reboot option.
Hopefully, the message won't come up the next time Windows comes up. You will, however, get a message about your configuration having changed. In fact, if you just click OK, you'll get this message after every reboot, however, if you click the checkbox before clicking OK, the message won't come up again unless and until you make another msconfig change.
Note that, if need be, any such changes can be reversed the same way they were made: The entries are not deleted, just deactivated.