Portals in the first game look basic on different computer. Please help.

[Lilac]

I'm using my sister's laptop while I'm on winter break as my computer is 300 miles away. I tried to play Portal, and the download was a success. Well, it was until...

"The portal will open in 3... 2... 1..."
*cue odd orange oval popping up*

Normally they look beautiful, but this was like opening a box of generic cookies. Totally not the same. Here's a link to a picture: http://imgur.com/VtHezkB

I have played the game on a worse computer and they looked fine. Can someone please tell me what's wrong and/or how to fix it? I can provide more information if it's needed. Thank you!

[Tealtyr]

DX levels or automatic setting changes I would think.

[nuh1]

It's the game defaulting back to directx8. Try adding -dxlevel 90 to the startup options to force it back to directx9, just make sure you take it out on the next load up or else it won't save your settings.