Well Daniel, I think UAC is a good thing but it's not for everyone. I come from a non-IBM PC background and remember Microsoft's Windows XP User Guide stressing "It's important to not use your computer for casual tasks under an administrator account - always create a Guest or at most a Power User for day to day work" but everybody ignored that, so they brought in UAC to address stupid users
But hey, i'm one of those people who's never used a so-called "Anti Virus" software (although I run scheduled scans per month still, I havn't been infected since WinXP SP2 days).
right now I installed xampp, indeed on another drive, not on my C.
I would have suggested that instead; but most users have a single partition. My bad! At least they used to... these days we have terabyte harddisks its more common to have partitioned data it seems.
I digress. Glad you solved the problem Jack
P.S. If you think your localhost might be a little slow on a bigger site, try configuring XAMPP things as services for more efficient thread-pool management (especially on Windows Server 2008)