Well, after my interesting COM+ Registry fiasco (and subsequent machine resetting), I'm pretty much back up to a running state.  I'm sure there are little things and setting here and there that I may have missed.  However, I did run into a particular 'Running as a Non-Administrator User' gotcha that I didn't experience previously.  The reason I didn't have this issue previously was because the last time I switched to running as a non-administrator, I was already well down the road of using my computer and many settings were already set.  This time, on the other hand, one of the first things I did was add myself as a regular user (relying on the MakeMeAdmin techniques for administrative promotion), so certain security setting weren't already assumed.

I use VSS (Visual SourceSafe) as my source code control system for individual and team-based projects.  In some cases I use SourceGear's Vault product.  I love both systems but must switch between them as I switch between work on various projects.  As a major convenience, Vault provides the ability to set Vault as the default via their 'Make Vault your default SCC Provider' option.  This is nice when you have the two source code control systems (such as VSS and Vault), though it might get more complicated with 3+ SCC systems (though there are utilities for this).

Well, since I'm not an admin I don't have the right to change the default provider.  This manifested in 1) Vault not showing the correct data and 2) Vault not being able to change the data (NOTE: it would work if I was temporarily promoted to admin).

As it turns out, you simply have to grant the appropriate permissions in the system registry to the following key:

HKLM\SOFTWARE\SourceCodeControlProvider

It's as easy as that.  Now, I wish the installers would set that permissions appropriately, rather than assume that I will have the permissions (e.g. running as admin).