Working on a customer's computer, I ran into an issue where right-clicking on My Computer, then clicking Manage would bring up an error box stating "Access Denied". Obviously, computer manager would not open. Not exactly sure what the problem was, I decided to do some research on it and found a few websites that explained the same problem with a "fix" of going into gpedit.exe and checking the policy related to computer manager. That is fine and dandy on a Windows XP Professional version, but XP Home is a different ballgame. The next fix was to manually check in the registry and see if the string was set to block access to computer manager. I checked a few places but didn't see anything out of the ordinary. What I DID notice however, was opening a command prompt and typing "regedit" brought up the classic error that it was an unrecognizable command. "That's weird..." I thought. I checked a few other common command line tools and they gave the same thing. So, I dug into the actual directory where regedit is located (C:\windows) and it opened without a problem.
That got me thinking that maybe the system variables were not set. This is something that back in the Windows 98 days and days of DOS, you would have to manually set some of the system variables and point where certain paths were. With Windows 2000 and XP (and later), these are pretty well taken care of out of the box.
Upon checking the system variables for the logged in user, I noticed that there were no User variables set and the required System variables such as PATH were not set either. I had a pretty good feeling that the missing information was the root to my problem and after adding the variables in, my problem was solved!
So, if you get an "Access Denied" box when right clicking on My Computer -> Manage, check the system variables first.
Now for the "How To" on setting up the right variables, if they happen to be missing:
1) Open the system properties (Easiest way is to right-click My Computer -> Properties) Long way is through Control Panel -> System
2) Click the Advanced tab
3) Click the Environment Variables button
4) Set (or verify) the following User variables for (username)
5) Set (or verify) the following System variables
Note: Keep in mind that other programs might add to the above variables. That's OK. There will be other variables listed and that's OK too. But, if the variables are blank or missing altogether, you should probably go ahead and add them in. The above variables "should" be the default ones that were setup when Windows was installed.
That should do it! Though the settings might take affect immediately, I still recommend that you reboot the computer.
If you don't know how to add a variable, click the New button, then add the above information into the "New Variable" box.
Variable name: TEMP
Variable value: %USERPROFILE%\Local Settings\Temp