Update: This issue is definitely related to the corp desktop policy - I've noticed that while working at home, disconnected from the corp net, I can browse localhost without issue.

I've recently discovered a really, really, really annoying irritant with Vista Enterprise over the last couple of days.  Here's the scenario:  For the past while, I've been getting my new laptop configured for development - installing Visual Studio (2008, no problem - 2005 is missing a .CAB - WTF?), Subversion, add-ins, etc.

I also installed a personal wiki to keep track of dev projects, info, etc.  Sure, I could use OneNote for this, but it's just not very... developer-ish.

All was well, until yesterday morning when I discovered I could no longer browse http://localhost.  I was able to get functionality briefly restored by disabling User Account Control (stops pestering you for elevated access to do routine tasks), but then in about 15 minutes, I was out of luck again.

It appears that I'm not the only one having this issue.  Here's what I was able to dig up from the intarwebs:

Steve Schofield - Localhost Connection Issues List

I've tried just about everything.  Even removed and re-installed IIS7.  This means that I'll probably have a lot of fun getting Virtual Server to run the web admin panel, as well.

My suspicion is that it's somehow tied back to the group policy that IT has set for the laptops.  I'll report more when I figure this out...