have you tried the pbsvc.exe to test your PB installation?
also what can you find you enter the error given in google?
Punkbusterlog file for 2142 default install: "C:\Program Files\Electronic Arts\Battlefield 2142\pb\pbcl.log" the pbcl.log file last line is the last given error/notice by pb.
check and current version of pb are:
2142: client: v2.018/a1375
cod4: client: v2.009/a1394
Beta: Latin for "still doesn't work".