I've meant to blog about this earlier but kept forgetting. Running Explorer (not Internet Explorer, just the My Computer variant) from an admin prompt when you’re a developing as a normal user takes a bit of trickery. Aaron Margosis has a couple good tips for working around this. I use the registry hack he mentions in the article, plus I’m a fan of his PrivBar add-in.
Check out his post: Aaron Margosis' WebLog : RunAs with Explorer.