Link problem somewhere

when I boot up, I get one of those open with dialogs looking for something to open the file C:\Program with. I hit cancel to get out of that, then get something saying that There is a file or folder named C:\Program that is causing problems and it wants to change it to C:\program1

Now Im guessing that its refering to C:\Program Files\, and that some program made some invalid shortcut or registry key (maybe they forgot the quotes so that C:\Program Files\blahproggy\proggy.exe should be "C:\Program Files\blahproggy\proggy.exe" (only difference is the quotes)

Now how can I track this down?
It has something to do with startup software cause only some of my programs load, and those error messages I spoke of happen only at startup (actually, the open with happens every time you reboot, and the Program to Program1 error happens when you either reboot or log on if it makes a difference)

I've kinda lyped this lazily, so ask me to clarify if you are confused :)

Look in your Startup folder, and in the registry, under current user/local machine/ software/microsoft/windows/run (or runeonce, or runonceex, or startservices or whatever). Delete things from there until the problem goes away. You can then fix the problem.