It will remove mebroot/sinow/TDL 4 there are different specialist tools for TDL 3/Helpassist as they use system files as well as the MBR so it needs a multi pronged approach to the repair

At the moment these are the main MBR infectors

However, it appears that there are now some variants that merge TDL3/TDL4 which makes it a tad more difficult to remove.

the author is from gmer.net (not avast.com):
That is his personal page, who do you think designed the MBR detection routines for Avast (aswMBR) ;D? The different versions are just the change log of the programme, the only one you can download will be the latest