Taskbar won't unlock, can't show hidden files/extensions, missing context menu items

Hi
I'm helping a friend who had a malware infection, which has now apparently been eradicated (thanks to the Malware Removal forum!). Vista Home Premium SP2 32bit. I don't know if the following problems are due to the malware, or if they were preexisting on my friend's computer. But I suspect they were used by the malware to protect itself.
*The taskbar won't unlock, even temporarily (in contrast to the folder properties issue mentioned below).
*I can't show hidden files/extensions, even temporarily.
*Folder properties can't be altered, e.g. the user documents folder is always displayed as "Pictures and Videos" type instead of "All Items" ; can't set to use Windows Classic folders, show full path in Title Bar, etc. They CAN be altered temporarily, but the previous settings revert on rebooting.)
*Context menu items such as new folder, new text document are not present.
*Deleted files do not show up in the recycle bin.

They did not return to normal after doing a system restore to 3 weeks before the time the malware became apparent. This was done before eliminating the malware. The following were tried afterwards:
I ran Unhide (from Bleepingcomputer) several times; no effect.
I ran System File Checker several times; the ~4 items that it couldn't repair don't seem related to these issues.
I've tried restoring the context menu items using the fixes shown here, but to no effect.
http://www.vistax64.com/tutorials/154554-new-context-menu-restore-default-menu-items.html

I was advised to merge this (as a file called fixme.reg) with the registry to unhide hidden files:
__
REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"Hidden"=dword:00000001
"SuperHidden"=dword:00000001
"ShowSuperHidden"=dword:00000001
"HideFileExt"=dword:00000000
__
but I get "Cannot import fixme.reg: error accessing the registry." (All antivirus programs were disabled at the time)

Is the registry locked, somehow? I'm ignorant about the registry, also new to Vista

One other (minor) funny thing, probably unrelated: Every time I restart Internet Explorer 8 (which I just updated to), it says it is not my default browser, do I want to set it as default? I always say yes. (Yes, I'll install FF4 & MSIE9 after other problems are solved)

Any suggestions?

 

Re: Taskbar won't unlock, can't show hidden files/extensions, missing context menu it

There was only one account on this computer. I created a new Admin account, and the New context menu items showed up in the new account.

So what does this say about what I need to do, to make them show up in the original admin account?

 

Re: Taskbar won't unlock, can't show hidden files/extensions, missing context menu it

Likewise, in the newly created account but not the original one, deleted items show up in the recycle bin. Why is that?