Hello, sham... you have some dodgy registry keys which were used once to unregister your shell32.dll, possibly so as to modify it, so let's fix those and see where we can go from there. Unfortunately at the moment I do not know what software is behind it.
Start hijackthis, select Scan Only, place checkmarks against all the entries listed below that still exist, and then press Fix Checked.
O4 - HKUS\S-1-5-19\..\RunOnce: [ShowDeskFix] regsvr32 /s /n /i:u shell32 (User 'LOCAL SERVICE')
O4 - HKUS\S-1-5-20\..\RunOnce: [ShowDeskFix] regsvr32 /s /n /i:u shell32 (User 'NETWORK SERVICE')
O4 - HKUS\S-1-5-18\..\RunOnce: [ShowDeskFix] regsvr32 /s /n /i:u shell32 (User 'SYSTEM')
O4 - HKUS\.DEFAULT\..\RunOnce: [ShowDeskFix] regsvr32 /s /n /i:u shell32 (User 'Default user')
O9 - Extra button: BitComet - {D18A0B52-D63C-4ed0-AFC6-C1E3DC1AF43A} - res://C:\Program Files\BitComet\tools\BitCometBHO_1.2.8.7.dll/206 (file missing)
Then go Start, and paste into the Run box:
sfc /scannow -you will require your installation cd.
When done, try an online scan such as Kaspersky.
http://www.kaspersky.com/virusscanner
Will MBAM update and run now?