Quickie Fix: IE8 Screwed Up Explorer Double Click
I installed IE8 yesterday. Not that I use it but <shrug> Windows Update.
Anyway, today I found that my Windows Explorer is suddenly opening a new window every time I double-click a folder on the right pane. It was driving me nuts until a quick Google found the answer.
Open cmd.exe as admin, and run this:
regsvr32 actxprxy.dll
That’s it! For me it fixed it instantly, no restart of Explorer required.
(Thanks to the article here for the info.)

