Many of my games no longer work in different ways

Have you already tried with uninstalling and reinstalling graphic drivers?
Recently, did you update the graphic drivers?

When you installed Bioschock, did you perform any kind of graphic update? Or directx update?

What power supply do you have and how long have you had this PC?

I would try these:

- Check event viewer after a freeze occurs and see if anything shows up under windows logs > application and windows logs > system
- Uninstall then reinstall GPU drivers
- Rotate RAM sticks (assuming you've got 2 x 4GB)
- Right-click on your HDD (whichever one the games are installed on), go to properties then the "tools" tab, under error-checking click "check"
- Run memtest (will take a good bit of time, might want to let it run overnight)

I would check that RAM.

Did you run the mem test? If yes, the single RAM stick did pass successfully the test?

When was the last time you cleaned out the actual hardware?
I get friends bringing me their pc's asking me to make them faster and when I open the case the fans are so caked their almost froze up. After I take it outside and hit it with compressed air I check all connections and remove the ram and gpu. Get a q-tip put some alcohol on it and clean those gold leads.

Snap it all back together and fire it up in safe mode to do any spyware or malware scans. ( I still like some of the free ones like spybot and malware bytes. ) Then I double check all start menu launch requests and clear anything that is not needed and change the browser options back to normal since they have in most case been taken over by some kind of adware like snapdoo or whatever.

I pull up the system specs and check the temps just to make sure fans are running at proper speeds and the cpu is at a safe temp. ( Performance can be affected by high temps ).

In some rare cases the pc is older and has so many installs and uninstalls that it's choked up with alot of non functioning programs and could benefit from a defrag.

Oh, I update drivers and netframework too.

If the RAM checks out and you are certain it's a software issue there is always the sure fire, last resort fix. NUKE the HDD with a program like dban.

CAUTION!!! THIS WILL REMOVE EVERYTHING!!!

I have only had to do this once but, it fixed whatever it was that screwed up my pc. I spent days trying everything I could think of and never did find out what it was.

If you get fed up with trying to fix it yourself and decide to take this route here are few things to remember.

1: TIME. Be sure to have plenty of free time cause the program itself will take many hours to finish depending on the size of your hdd and then the fun of re-installing EVERYTHING begins. Of course this is only after you have saved everything you want to keep on flash or roms. Don't keep any programs that can simply be re-installed fresh and new from the maker. Focus on the stuff that is important like family videos and photos, favorite music,etc. Clear your weekend cause if your like me and it's a full HDD this whole process could take 2 days.

2: Make sure you have all your basic drivers saved to a disc if you no longer have the original disk. Ethernet adapters, after market keyboards/mouse, graphics card, etc. If it's DELL or HP you can get them easily at their site and just put your model in and all driver sets for that model can be downloaded and saved to a disk. MAKE SURE YOU HAVE THE ETHERNET ADAPTER and LAN DRIVERS as it is hard to do much without internet access. Your gonna want to make sure you have your OS disk as well( Windows ). I would not keep anything that you have installed around the time you noticed a problem like say a new scanner/copier, camera, etc. ( Just in case they created a conflict somewhere )

3: Make sure you have all your account names and passwords written down from anything you use like steam for instance. I tend to use different passwords for my stuff and when doing it all in the same day I found myself entering the wrong ones and wished I had a list to make it quicker and easier.

4: When you copy DBAN to a disk make sure to properly mark it as dangerous. put skulls or whatever on it so your girlfriend don't find it later and throw it in wondering what it is...in fact you may want to hide or burn it afterwards so she won't do it out of spite. : ) Mine threatened me with it after she knew what it was...

5: Before you begin this task make sure to unplug everything from your pc as it will erase the memory of anything attached. Don't go leaving that flash card you put your stuff on plugged into the usb port cause it will wipe it out too. The keyboard is all you wanna leave attached.


After you are sure you got everything you want to keep and have removed everything from pc launch DBAN and let it do it's thing on auto. It will go through the hdd 3 times so this can and will take a while.
When it is finished, remove the disk and put your OS disk in. Install Windows and begin the long update process ( You may have to install LAN or ETHERNET drivers for internet access then update). Once you have that it is time to put your driver disk in and install all of them.
Now you should have internet access to regain all your programs and games. I would do a fresh install from the sites if you can since you don't know what was wrong with the software to begin with.

If I were you, I would try to re-install the OS into a free HDD or SSD if you have one and check if it has the same problem, so you can understand if it is a software or HW problem.