Parallels Tools won't install - admin rights issue

When I installed the 5600 build, P.Tools gave an error message that I don't have admin rights to install. Checked with our IT staff, and they verified that I'm an admin for my WinXP Pro installation.

I've never had a problem with this in the past, and have even tried downgrading to 5582, but had the same problem again (which did not happen when I originally updated to 5582).

I recently installed XP SP3, so uninstalled that, and had the same problem.

I'm currently back to 5600 and SP3, and still can't update P.Tools.

Any idea why I'm getting this message?

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