Problem with Portal

[Dr.bob7]

well I can run Portal on my computer but at the very start when your in your cell It runs fine, as soon as the portal opens and I go through it the game quits and the report says hl2.exe (guessing portal uses hal lifes engine) incountered an error and had to quit, this happened 3 times in a row, should I reninstall or what?

[pepper_airborne]

It would be best to delete the content in steam and then refresh it so you got a nice clean set-up, if the problem persists after this then it would be best to check all the system requirements and see if anything could be hogging up your PC. Also try updating all of your drivers.

[Wii]

With Vista you have to run HL2.exe/portal as admin.
Just my guess