Have read different opinions on removing, or not removing Rootkits.
There are quite a number of forums that deal with Rootkits on a daily basis, successfully!
The option to reformat is always there, but, there seem to be more Users cleaning the computer (with assistance from the forums) than doing a wipe and clean install.
Personally, after loaning my laptop to a neighbor, upon return it had a rootkit. Took action to remove it, and now posting from it. It wasn't easy to get rid of, but, the computer is stable, and no further problems developed.
There are tools available to remove Rootkits that do a great job, and experts agree that more than one should be used to confirm removal.
Bottom line appears to be that it is up to the User on whether to clean the computer, or do a total wipe and clean install.