Take a look at this:
http://groups.google.com/group/micro...598fce8f80f60f.
I actually doubt it has to do with TweakUI, for them or for you, as I've ran that great utility from Microsoft just fine, but the people involved were running W2K and not XP, which is what TweakUI was made for (XP). I'm not altogether certain all the different stuff involved, for them or for you, but I do know how to get your logon/logoff sounds working again.
It sounds like the profile, or perhaps more specifically, perhaps just the ntuser.dat file has become corrupted. A new profile and profile migration is in order.
Go to the registry. Your key you will be looking for is HKLM\Software\Microsoft\WindowsNT\CurrentVersion\ProfileList. Find the key in there that corresponds with your present/old username (click on the subkeys there, check the path in the right-hand-side window, look for C:\Documents and Settings\usernamehere). Delete your present username's key, but ONLY that key - and note, you will be unable to log into your computer with that account - if it's the only one on the machine besides the built-in "Administrator", you may want to create another admin account before my next step I'm giving and log into that instead of Safe Mode as I'm describing. Reboot. Start up in Safe Mode by hitting F8 just after your motherboard BIOS finishes, choose Safe Mode from the menu. This way you can be logged in as "Administrator" and out of your old profile, and don't have to create any unnecessary profiles/accounts on the machine. Rename your old profile's folder in C:\Documents and Settings from something like, auggief to auggief.old, for instance, if auggief were your profile folder there. Reboot and log in like you normally do (automatic log in should work the same as it did before now that your old folder is renamed). Turn on hidden folders (Tools, Folder Options, View tab, Show hidden files and folders in a Windows Explorer window). Open up two Explorer windows side-by-side, one to, for example, C:\Documents and Settings\auggief and one to C:\Documents and Settings\auggief.old. You will want to copy the following folders' contents from these old folders into the new folders: Application Data, Cookies (only if you have saved passwords for websites, otherwise I'd forget these), Desktop, (My) Documents, Favorites, (My) Recent(s) (Documents), NetHood, SendTo, Start Menu, Templates. Parenthesis are because sometimes the names are a little different depending on the configuration (Domain vs. Local account, Pro vs. Home Edition or W2K). Then you will want to go into the Local Settings folder and grab just the Application Data and maybe your History folder if you care about links being purple instead of blue that you've been to before, and copy it to the same place in the new profile. Don't copy anything but those folders - you should be leaving behind the UserData, WINDOWS, ntuser.dat, ntuser.dat.LOG, and maybe some miscellaneous other small files there. You can then delete your old "auggief.old" account folder in Documents and Settings. Hopefully that should work/help if you were able to follow.
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