Streaming will not start

[WireDelta]

Bit of a long story here.
I have my old laptop currently hooked up to my TV. It plays games fine (it was a gaming laptop... back in 2008)
But recently, I tried playing Half-Life 2 again. For some reason, it wouldn't start. No errors, no crashes, it would just say "Preparing to launch..." and disappear. Checking task manager, hl2.exe is there and apparently running, but using up no CPU, and the game never starts.
Steam even thinks the game is still running and won't let me open another one without ending the first one's process.
I've searched these forums and google for hours trying to see if anyone else has had this problem, to no avail.
I've tried everything trying to get it to work. I've uninstalled both the game and Steam entirely twice, verified the game cache, changed settings, made sure everything is fully up to date, and yet nothing produces even a slightly different response. Still just a hidden hl2.exe doing nothing.

That's when I discovered In-Home Streaming. It was like a gift from the gaming gods. I have a much more powerful and more recent PC in my room now, and I thought if I could stream from that, it would solve all my problems!

Turns out, streaming on this laptop has the EXACT SAME RESULT. It tells me "Preparing to stream" and disappears. streaming_client.exe is running in the background doing nothing. The game even comes up fine on my PC. I just can't see it or control it from my laptop. I even tried streaming a different (much simpler) game the other way around, and that worked just fine!

Why? Why does this laptop refuse to run both Half-Life 2 and In-Home Streaming the exact same way?? It handles many other games just fine, even ones way more recent than HL2.

Laptop specs:
ASUS F8
Intel Core 2 Duo CPU @ 2.00GHz
3.00GB RAM
ATI Mobility Radeon HD 3650