Salsa_Shark: I think it may be because my internet connection is so slow. all these problems happen on both of my computers. Everything works fine in offline mode but when im online it stops responding whenever i try to do anything. I uninstalled my antivirus a few days ago and i defrag every week so i doubt they are the problems.
That's probably it.
Try adding these commands to your autoexec file:
cl_updaterate=60
cl_cmdrate=60
This will make it max out on 60fps but put less load on your internet connection, try lowering the numbers in 5-10 increments (if it doesn't work right away). Hope it helps!
if you don't know how to setup a autoexec file:
Make a text file in this directory. (Make sure the extension (.cfg) is a .cfg.)
<Steam Folder>\SteamApps\<account_name>\team fortress 2\tf\cfg\autoexec.cfg
Then paste the "cl_updaterate=60 cl_cmdrate=60" into the file.
You can remove the command if something goes wrong by deleting the autoexec file or deleting the commands within.
This will only help if you can even get into Team Fortress 2, if not then it's probably time for a re-install of steam. (or a faster ISP ;))