How to edit the registry in Windows 7
Typing "reg" and not finding regedit is a symptom of Windows 7's search--it won't find an item based on 3 or fewer characters unless you have found it once already. After you type "regedit" and run, the next time you type "reg", it should find regedit.exe.
Type regedit in the search box and hit Enter.
Typing
regedit
In the search bar and pressing enter brings it up fine for me.
Typing "regedit" in the "Run" window works as well.