I'm pleased you've managed to solve the problem, but for future reference (and because other people reading this won't be able to ask your admin to reset their profile), there are a couple of tools which can compact the registry hives:
NTRegOpt seems to be the preferred tool.
RegCompact Pro is another.
Both these tools are freeware, though RegCompact Pro has the noisy garish look of shareware; I always get the feeling it's going to ask me for $25 before finishing.
Also both tools will pretty much disable your PC while running, because they need almost exclusive access to the Registry while they work; and they'll seem to grind away for so long that you'll wonder if it's crashed.
Relax. Be patient, and let them do their job.
As ever, take backups of the registry before you start fiddling; and you'll probably get better results if you first uninstall as much rarely-used junk as you can, and let CCleaner have a look before compacting.