HL2.exe is not responding

[iusehax]

Firstly sorry if this is the wrong part of the forums.....

Specs i think...

Model: ASUS x71q notebook series
Pentium(R) dual-core CPU @ 2.00ghz
Memory ram 3.00gb
32 bit operating system
windows vista service pack 2
generic pnp monitor on mobile intel (R) 4 series express chipset family

What happens is i open up gmod css or portal and it just goes black so i cntl alt del and it says hl2.exe is not responding.

Any help? ive tryed -dxlevel 80 and run as admin.

Also CSS used to work until 1-2 months ago when it decided to follow the path of g mod.
Please help me as i dont like playing on my Home computer as its downstairs in a family room.

Thanks.

[TheSpy]

thats normal. it crashed on me just now

[iusehax]

But i cant play or open the menu it always crashes.