I posted about this in the forum last week and haven't heard back.

I recently switched over to a new computer that came with Vista 64-bit with an upgrade option for Windows 7 Pro 64-bit.  When I recieved the system (with Vista 64), I attempted to install PCA 12.5 and the install would hang when it got to a step where it said "Adding Shortcuts" (with 1 second to go).  It would never complete and I would have to cancel the install.

When I upgraded my computer to Windows 7 Professional 64-bit.  The PCA 12.5 installation hangs at the exact same point that it did under Vista 64.

I've tried countless times to do this installation and I'm considering trying a scratch install of the OS on this machine because PCA is so important to me.   I'm wondering if PCA is conflicting with some of the pre-installed Dell utilities.  Under Windows 7 64bit, it acts exactly like it did in Vista 64bit.

The funny thing is: When it gets to that "Adding Shortcuts" stage where it never completes, I've learned that if I do a hard powerdown at that point (pull the power plug with no battery).  When it restarts, I can actually use PCAnywhere.  This was the case with Vista and again in Win7.  However, the PCA install is then in a Suspended state and it will prevent me from installing other software before I deal with it.  So then I end up removing the suspended PCA installation.

Wish I had better info to offer.

I have seen this in a 32bit xp and vista before.  Try performing a clean boot so that all services except microsoft services are stoped and then try the install again.
http://support.microsoft.com/kb/310353  this one is XP but reads better and is about the same steps.
http://support.microsoft.com/kb/950093 Here is the vista one. 

Clean booting would help resolve the issue if it is a conflict with another application.

Cheers.