This first started happening maybe six or more months ago. It started as a result of a Windows Live update that ended up installing far more crap than I wanted. At the time, I tried briefly to resolve it, but failed. Today, I tried very hard to fix it--all to no avail.
I found a number of suggestions that seem to have worked for others with the same problem...but not for me. I tried the two "msiexec /x..." suggested that supposedly delete the offending program. In both cases, it says the product must be installed before I can delete it. (I did a copy and paste, so it wasn't a typo on my part.)
I tired running the Microsoft Fixit 50060 which ran clean but the problem persists.
I went into the registry and changed all occurrences of the path to insert quotes around it. (The implication was that the path had spaces and should be quoted.) The problem persists. I am at my wit's end.
The only thing I haven't done is delete the "Microsoft" folder. I'm afraid I might be trading one error for another, possibly more grave error.