what an interesting "style" of "posting" where one can't tell what exactly is it that you said in the whole thread. in first post you mention something about version 1.45 not being compatible with..uhm...something. in this post above you're not making any sense whatsoever. the correct answer, as experienced by me just now is the following: both offline update file found here http://www.gt500.org/malwarebytes/ AND the method of copying rules.ref (from updated machine) to "C:\Documents and Settings\All Users\Application Data\Malwarebytes\Malwarebytes' Anti-Malware" on target machine, work as expected if one for example installs version 1.50 of mbam(same version of mbam installed on both machines). only issue is that info (given in program's pop-up window) about database age is wrong, but that doesn't matter, as database is indeed new (mbam-rules.exe is a bit older, naturally, but not much...) as you can see on the "update" tab of the program (there's date of database there) and thing just works, with both ways of updating rules.ref on a pc not connected to the web. this was written in december 2010 (if somebody fails to see the date of this post). i hope this post satisfies the curiosity of those who need to update mbam definitions on offline pcs.