For several days my pc began to behave very slowly. For a day or two Outlook would suddenly stop downloading new messages, saying that another application has locked the .pst file.

Yesterday I suddenly saw a ZA message (I have ZA Extreme Security installed) saying that it had found a virus during a scan and asked me to close all applications so that it could apply advanced disinfection, after which a reboot would be required. I okayed it, and no reboot resulted. The file seemed to be associated with the Uniblue registry booster.

I was suspicious, and prepared for a full system scan. I tried to update the signature files, but ZA was unable to do so. I started the full scan anyway. About 17% of the way through it stopped in a very similar manner, but with a different file. In both cases it mentioned Launcher.exe . The error message was "Malware has been detected that requires advanced disinfection to be properly treated. If run, the system will be automatically restarted after completio. Please close any open documents. Do you want to allow this." In the first case (previous paragraph), I clicked "yes". In the second, I clicked "no". In both cases, it proceeded anyway, and then the scan continued after treatment.

Another notice was common to these two instances: "The application or DLL [path name] is not a valid Windows image. Please check against your installation diskette." In one case the identified path was C:\Documents and Settings\Bill\Application Data\Uniblue\Registry Booster\_temp\ub.exe and the other was C:\WINDOWS\system32\mstm13.dl .

In one case the identified infection was Trojan-FakeAV.Win32.RegBoster.a . [The misspelling of Booster was in the identified on-screen message.]

My full system scan is still running (it takes about 15 hours). What's next?

BTW: I tried to run Malwarebytes, which I have used multiple times in the past. I received an error message: "The application or DLL C:\Program Files\Malwarebytes' Anti-Malware\mbabm.exe is not a valid Win32 application."