Have been running HL2 with no problems for months, then after adding another gig of memory to my pc, have been having problems. Specifically game has been freezing, with the sound looping fast. Pc freezes, and won't allow me to close game down, so have to shut off and reboot. All other programs run fine, and Pc runs smoothly, however, if i take memory upgrade out, game goes back to running fine.
Steam check says my firewall (zonealarm) may cause probs, but it seems to run fine once memory out. Memory upgrade is 2 PNY 512Mb pc3200 dimm, ddr 400Mhz, bringing me up to 2gig.