Can't join MP servers.

Okay, so I haven’t really been trying to get on them much in the past few months, but recently, I wanted to do some multiplayer. My problem is, I start to connect, then my computer divides by zero, or something, then it throws me out.

In the past, I played this on my desktop, with not too many problems. I’m not sure whether I have played MP on my notebook, but I think I have. I remember that at the parsing part of connecting, you get those 500 files all the servers want you to have. For some reason, now it skips that phase, and continues on to something like “Sending Client…”, or, “Downloading server…” But when this step happens, the little “Files needed from server: 50,000,000” message pops up. It’s not really fifty million, but it can’t download them or something, then throws me out of GMod with some generic “GMod has stopped working” message, with no solution.
Any help (Leading to my problem being solved) is appreciated.
Thanks,
Scotty A. Loser.

you can join other servers?

No, I can’t. I have tried enough to know it’s not going to let me join anything worth playing.

Specs?

Windows 7 Home Premium (x64) (build 7600)
2.20 gigahertz Intel Pentium Dual-Core
64 kilobyte primary memory cache
1024 kilobyte secondary memory cache
64-bit ready
Multi-core (2 total)
Not hyper-threaded

[editline]01:14PM[/editline]

Windows 7 Home Premium (x64) (build 7600)
2.20 gigahertz Intel Pentium Dual-Core
64 kilobyte primary memory cache
1024 kilobyte secondary memory cache
64-bit ready
Multi-core (2 total)
Not hyper-threaded