hl2.exe crash when joining second server Urgent Reply!

When I join another server after being on a server I get a “hl2.exe has encountered a problem and has closed”, is there any way of fixing this, as I have already uninstalled and reinstalled the game via steam. My graphics card is an Ati Radeon Xpress 200 but I will be getting a new one soon. My gmod plays smoothly in game but Ineed this problem fixed. Stop ignoring my help requests, garry should be helping as well, ignnoring is useless and pisses me off. So reply. I have posted this again so people will help me.