Shoutbox

I'd say

ctrl+alt+del, kill the extra csrss.exe first and then block-checker.exe (if you don't know which csrss.exe it is, use Process Explorer from sysinternals to see its path)

Then delete the contents of C:\Program Files\Block Checker and edit startup to stop block-checker.exe attempting to start.

Try find the ini files in the system directory, if you can't find them there then do a Windows search and see if they're located anywhere else for some reason.

It's probably not really needed, but I guess an adware/spyware scan can't hurt.