Can't cure MBR?

I'm in the middle of running a scan for a rootkit problem my Avast previously detected, and says I have. I've gotten on to your site, and am using the "sticky" thread re: virus/malware removal. After having downloaded all the programs you say to download, and running them in the prescribed order, I'm at the stage of running TDSS Killer. During this run, I've gotten a pop-up saying "Can't Cure MBR. Write standard boot code?" I've gotten this message after following instructions as specified, and have not altered anything in TDSS's settings. What should I be doing now?rolleyes

PS May be helpful to describe the rootkit message I've been getting - this has to do with "MBR - Wistler-A". About two days ago I experienced problems with my Yahoo email account (DAEMON non-deliverable mail notifications from months ago, emails to myself, and other anomalies). I suspect I was hacked and the account hijacked for spamming.

 

Had medical appts to take wife to today - left house at 1000A with situation as reported - came back at 400P with Kaspersky frozen, saying "Cure in Progress" but nothing has happened. I did save the report generated by the application, however. Since the program said it could not cure the MBR, and it would have to take the action stated in the previous email in this thread - should I just terminate the Kaspersky app, restart it, and see what happens?

 

TDSSKiller box now on desktop, I can not get rid of it even with Task Manager. All I can do is minimize.

 

Understood. I held off due to a notice on the TDSSKiller dialog box saying it was going to edit or otherwise change the bootup procedure for the computer. THAT made me think twice.
At any rate, will complete the process and report results.