Just wanted to post this hoping I could save someone the pain I went through. I was running Windows 7 Ultimate 32-bit on my game machine, and decided I wanted to install the 64-bit version to see the difference.
When I was done, the system was identical to the way it was before, except now it was 64-bit. Same programs, anti-virus, everything. All my games ran beautifuly, except for Steam. None of my games I bought through Steam would run, though they ran fine in the 32 bit version of Windows 7 Ultimate. The games would act like they were going to run, but then nothing. It would just drop out to the desktop.
No problem, I thought, I will just contact Steam. Well, to make a long, very frustrating story short, it took about a month and a half to get it working. It turned out that 64-bit Steam client does not like PCTools Anti-Virus runing at all. It had to be completely shutdown and disabled before any games will run. The strange thing is that I had no problems at all running Steam and PCTools on my 32-bit version of Windows 7.
I give Steam support an F-. They would have you try something, you would try it, then it would take them a week sometimes to get back to you. Demanding to be escalated to a higher level of support or to speak to a manager does nothing. Also, asking for a contact number or trying to find a phone number for Steam is also a waste of time. I found three numbers for Steam, and none of them worked.
I have been a very long time Steam user and never really had any problems. But, when I finally did, it seems that Steam went out of it’s way to make it difficult to get support.