HL2 Graphics Problems

[Braveheart]

Whilst playing and loading up the game, there are numerous white lines all over the screen, particularly in areas which are set indoors.

Any ideas as to the cause of this?

 

[Mutley]

Are the white lines where textures change or ground changes in direction, like corners of walls and slopes?

What graphics card are you using?

 

[Beerdude26]

First, try this : steam://validate//220
Now, if that doesn't work, please give us your system specifications. (Tutorial can be found here : Link)