I recently built a new pc with the following specs:
 
Intel E6750
Gigabyte GA-P35-DS3R
Corsair XMS2 PC2-6400
eVGA 8800 GTX
WD 36GB Raptor HDD for OS
WD 320GB Caviar SE16 HDD
ASUS E616A3T SATA DVD-ROM
Plextor PX-800 DVD burner
Viewsonic vx2035wm monitor
PC P&C Silencer 610W PSU
Antec P180b case
Logitech X-230 speakers
Logitech MK3200 wireless desktop
Windows Vista Home Premium 32-bit
 
Nothing is OC'd or altered. Everything is running at stock speeds/specs. I've got the latest drivers for my GPU and MoBo (as none of my other hardware needs any drivers).
 
Soon after building and OS installation and updating, I installed Steam and downloaded my HL2 games (HL2, HL2:Ep1, HL2eathmatch, HL2:Lost Coast). Everything runs smoothly, except when I tried playing HL2:Ep1. The first crash happened during loading of the next area. Anytime I got to a point where the game had to load the next area, the game would crash and I got this error about hl2.exe has stopped working. If I restarted the game, though, I could get through that load point, until I got to the next one and the game would crash again. So I went through the game always crashing at load points and restarting and I could get through until the next one. The problem then persisted in HL2: Deathmatch. When loading the next map, sometimes, not always, the game would crash and I'd get the same message as before. Also, it sometimes crashes in the middle of gameplay giving the same error. I then noticed that when I start up either of the two games, I get a message saying hl2.exe is not responding and I can choose to either terminate it or wait for it to respond. If I do nothing or choose to wait, the game loads and it works for a while until it crashes like I previously mentioned. The crashes don't happen right away. I've usually been playing for a while before it happens. I haven't noticed any problems with the original HL2 game, only Ep1 and Deathmatch. It's pretty annoying and I can't seem to find anyone out there having the same exact problem who could fix it. I'm thinking it's a driver error with my video card and I just have to wait until new ones come out and hope they work, although I'm hoping there's someone out there with same/similar hardware and running HL2 games. Does anyone have any ideas what could be causing the problem?
 
Additional info: I've been running both games with visual options maxed. I figure I got my GTX now, I gotta pump everything up.
 
Also, on a possibly related note, I got a free copy of Company of Heroes with some hardware my brother bought. I installed it and also installed the DX10 patch that came with the game. First thing I noticed was that with all the visual options maxed out, I got an average fps of like 60 when I ran the performance test. I was thinking I should do better than that running an 8800 GTX. Secondly, Once or twice now, the game froze/crashed when loading the next mission. I've got a feeling it's related to the HL2 problem (drivers maybe?)
 
Any thoughts/insight is appreciated. Thanks for reading and posting!

As far as fps goes, I presume you use a refresh rate of 60Hz?  The refresh rate is what limits fps to 60.
 
In regards to your problem.... how much RAM are you running?  Have you run Memtest86?  And have you tried reinstalling the game and/or installing the latest Dx?

Ok, I guess that makes sense about the fps. About the memory, I have 2x1GB of memory. That should be plenty for what I'm doing. I tried reinstalling and I got the same problem. Well, at least one time it happened. I'll try the Memtest thing and getting the latest Dx.

Just a thought: I have Vista 64-bit and I know that the security measures can be a pain.  Go to the properties of the shortcut to HL2, and maybe run it in compatibility mode for XP - also run it as administrator if you haven't already.
 
One other thing... you said the crash tends to happen more often when loading maps?  I see that you have 2 HDD's - try installing HL2 onto both of them???  

I just got the error today after quitting CS:S, i've never had it before, but I haven't played HL2 on this system until today (just got it, core 2 quad q6600, also vista 32bit).
 
I haven't seen it crash while loading maps, the only time I saw it was when I quit CS:S

Well I tried running it in XP compatibility mode and it still crashed. I am the administrator on the computer so that's not an issue. Still haven't tried installing it on both HDDs. But I don't think it should make a difference. Any other ideas? Thanks for the help so far.

Depends if you've run Memtest86 or not; I only suggest the installation on the other HDD because it seems odd that it would occur when loading a new map...
 
I wonder if it's just Vista related problems.  Try an error-checking yet on your HDDs?

I've had the same problem with my computer.  I've made it through probably 25% of the game and am now this problem is creeping up all the sudden.  What gives??  My specs:
 
Gigabyte EX38T-DQ6
Intel Q9450
EVGA e-GeForce 8800 GTS (512MB)
Corsair 2GB (2x1GB) SDRAM DDR3 1333MHz
Seagate Barracuda ST3250410AS 250GB 7200 RPM SATA  
Vista 64 bit w/ SP1
 
Looks like this thread is old, but any responses would be appreciated.

PROBLEM SOLVED!  Halleluiah!  Praise the damn lord!  I found on a different thread the answer to my problem and thought I'd post it to help any poor suckas like me who just want to play their damn game!  
 
Originally Posted by suid  
DISABLE YOUR STEAM INGAME STEAM COMMUNITY.
 
Click on community tab.
 
Click on settings.
 
Click on In-Game Tab.
 
Un-check the 'show ingame' box
 
Retry loading your game.
 
Cheers!!
 
(This was posted previously in the thread but looks like its been getting missed over, so i'm making it a bit more apparent)
 
Adam
GaloreGameServers.com

Good to hear you got it working!