|The Taskbar and Start Menu icon should show four tabs which enable you to tick boxes and therefore make settings. Obviously this is no longer the case. |
It is difficult to know quite where to go from here. You mentioned a virus so I assume all this came about after the system was infected.
The big guns (if you have them) would be to to run any supplied restore disk (or Vista CD) which would of-course lose all your personal data and programs.
If you want to get to places you cannot access (to sniff around) then you could create a Linux Live CD on another computer, such as Puppy Linux. You burn the CD using "burn an image (ISO)" feature - from the download. To run it on this computer you first have to go into BIOS to make sure the CD is set ahead of the C drive. You then boot with the CD in the drive and Puppy (or whatever) will run straight from the CD using RAM and will not touch your Vista installation. Note that everything is single click in Linux.
By the above means you could drag your important data from HD onto a Flash Drive. It will also allow you to examine your HD file structure, including the log you mentioned. The file cfgmgr32.dll is located in C:\Windows\System32 if you wish to see if it is present, or even replace it.
Another possibility is to run system restore (back to when things were working properly) from Safe Mode. If all else fails use the procedure already given in #1 and type rstrui.exe via cmd.exe - this should start restore.
As a long shot you might be able to run MalwareBytes free version from Windows Safe Mode by changing it's exe file to either cmd or bat (if necessary). This applies to both the downloaded exe and the program file itself. The ability to run MalwareBytes with these other file extensions was deliberately built into it because so often viruses disable the running of exe files.
Sorry, I can't give you some clever fix for this issue but only provide ideas which might help you to see a way to tackle it. Unfortunately it seems like this virus might have badly screwed things up and maybe the registry fixers wrecked things a bit more too.
Please come back and let us know how you got on.