It seems that the installed integration components are corrupted, and that's causing re-installation to fail. First thing to try is to do a System restore to an earlier point in XP Mode. System restore in XP can be found like this:
Go back as far as needed to be sure Integration worked at that point.
If that does not help, I'm afraid there's nothing much to do except reinstalling. Assuming you have not changed the default setup, XP Mode uses two virtual hard disks, a base vhd and a user specific vhd (check this
post if this is unfamiliar to you).
Because of the way these so called XP Mode differencing vhd's work, the integration components are installed on the user vhd, not on the base. Due this, it might not work to make a copy of your vhd, reinstall XP Mode and create a new virtual machine using the old XP Mode vhd. But, at least it is worth to try. This
post was an answer to another member who wanted to copy XP Mode to another computer. Although different situation, you can use that method to make a copy of your vhd and after reinstalling XP Mode create a new vm.
If this fails, then (sorry!) there's nothing else to do than reinstall all apps on new reinstalled XP Mode.
For future reference, here's
a list of all possible XP Mode files and their default locations.