Are you talking about 2 RAM modules of the same frequency ( eg: 400MHz, 333MHz, 266MHz ) or different frequency.
The 'sounds of switching off', do you mean that the system speaker gives some beeping.
The Blue Screen that you have seen must be the Blue Screen Of Death ( aka: BSOD, google for BSOD or search this forum for BSOD ).
It would be better if you can give more info:
Like what is the Operating System you are using?
Give a full system Spec as far as your knowledge?
Please note the error code on the BSOD, it should be something like this:
0x0000004e (0x00000099, 0x00000000, 0x00000000, 0x00000000)
Try 'memtest' and see if you can find fault with it.get memtest at:
www.memtest86.com/
Also since you have removed your modules, try with one at a time and see if the problem reccurs.
If it does not you might still confirm your findings with memtest
Physically cleaning your modules might not be the solution to your problem.
Anyway, the problem your are facing while fixing the module,might be a smiple error in the technique.
Make sure that, the module is placed facing the correct direction, i.e. see the notches on the SLOT and the MODULE -- make sure they are matching and just press in the middle slowly. DO not force it. (please do everything with the POWER OFF )
It should 'click' into position quite naturally. If NOT, you are doing something wrong. Get expert help *( vendor )
