.b1 free archiver is dirty as fuck. if you sandbox it you can extract the clean bits out without the virus.pup's, but it's also attained from looking in the ini files or something as you will be able to read the links that the installer uses to download the actual archiver problem
MOST SIMPLE FIX - use the open source .b1 jar tool that the douchebag's that made the archiver (legally) used to try and scam people. I couldn't find the website and too dik to find it, but if you google the max outta that shit you will find the open source version.
Here is the .jar and the help file you revieve when you 'java -jar b1.jar -h' it, as well as some examples I put in for the noobs; and a .bat if you wanna throw the b1.jar and b1.bat in your %PATH% so that you can have an auto extractor e.g.
mkdir "b1.out_%~1"
java -jar x:\path_to_b1.jar x -o "b1.out_%~1" "%~1"
Only open/use what you are able to understand; if need be that you must proceed ya'd better get to the learning
Would have been a funny but cruel joke to pack all this .b1 shit in a .b1 archive lol.. thought about it but in a good mood today, plus IDK how old this shit is I just wanted to share what I encountered in my experiences with .b1 archives (mostly found from grabbin' shared shit on 4shared)