Windows 7: Please, please help! SF Diagnostic Tool uploaded

Hi. I have had my PC perfectly running since 2010. I have played all kind of video games with no problem with my GXT 580. Recently I hired and installer to add more ram to my PC and a SSD drive. He tried for a lot of time to install the additional ram and did some stuff on the bios with no avail. He then told me that he was going to leave the PC at that (with the original ram) and installed the SSD. Everything was great and I have been using my PC for almost 6 months without problems. The problems started last week when I decided to play again some video games. Whenever I was playing games (Planet Side 2 or GTAIV) then the infamous BSOD appeared. I think that if I never played any video games (since the new installation) I would have never experience the BSOD. I highly suspect of something the installer did. Please, please help me!! Thank you so very much!!!

Update your BIOS.
Daemon Tools, Alcohol 120% and Power Archiver Pro uses SCSI Pass Through Direct (SPTD), which is a well known BSOD causer. Uninstall Daemon Tools at first. Then download SPTD standalone installer from Disk-Tools.com, and execute the downloaded file as guided below :

• Double click to open it.
• Click this button only:
• 
• If it is grayed out, as in the picture, there is no more SPTD in your system, and you just close the window.

Update your Samsung SSD's Firmware.

Update XBox USB wireless controllerdriver (must) from Software Downloads | Microsoft Hardware

Free up the startup.

1. Click on the Start button
2. Type “msconfig (without quotes), click the resulting link. It will open the System Configuration window.
3. Select the “Startup” tab.
4. Deselect all items other than the antivirus.
5. Apply > OK
6. Accept then restart.

Let us know it the problem persists or not.

Thank you very much for your answer and for taking the time to help me. I did follow all your instructions but after several minutes playing the BSOD happened again. It is only when I'm playing games, that is, when my PC is "working" a lot I guess.
Do you think is memory related? I have had that memory since 2010 when I bought my PC with no issues. Does memory tend to fail over the time?
Should I buy new memory?
Thank you!!!!

Stress test the Graphics Card using Furmark.
Video Card - Stress Test with Furmark

Test your RAM modules for possible errors.
How to Test and Diagnose RAM Issues with Memtest86+
Run memtest for at least 8 passes, preferably overnight.

Is the computer hot? Report us the heat of the computer after a couple of hours of your normal usage. Upload a screenshot of the summery tab of Speccy.