From what I have seen this may be related to a Microsoft Office SP2 upgrade. Note, I don't mean Windows XP SP2.
You will need to unpack the SP2 executable, find this file, then point the file path to that file. More details here;
Note: To see the offered solutions at Experts Exchange, you need to scroll down beyond the tabled adverts.
There is also a suggestion by the poster there that his Windows Installer had become corrupt, so you may need to research Microsoft's Windows Installer Cleanup Utility.
I hope that helps.
When I try to run Excel or Word (2003) on a machine in the Lab (XP SP2), I get a message that it "couldn't find mainsp2ff.msp"..... I searched the whole disc but cannot find such a file. If I click OK it just repeats itself; if I click Cancel it goes away and Excel/Word run just fine.
How can I remedy this, or disable/uninstall whatever it is so that it will cease to pester?