BSOD differents bsod ntoskrnl.exe in many months

[mrday]

Hello,
first thing: this is not my pc, so I have experienced just 1 of this bsod (chronologically the last one: this pc had 2 cd/dvd reader, 1 working and 1 not working, to do some tests, I disconnected the working one, at first start the broken one has worked but it gave me that BSOD).

Another info: after the 30/11 an external graphic card was installed (don't know which driver/version).

All the older BSOD (before the 21/01/2015) was not caused by me. I ask you, gently, to have a look at this dumps and help me to find the problem/s. Thank you

 

[mrday]

HD3650 + Acer T650-99TZ compatibility issue?

Hello,
some days ago a friend took me his pc because he had got many BSOD (I posted yesterday about that with no luck), many of this BSOD are happened after I have installed in that pc an ATI HD 3650 PCI.

First test group on this machine (Acer T650-99TZ):
prime95: rounding was 0.5, expected less than 0.4 (after 2 minutes)
memtest86: many errors whit 2 stick of ram, 0 errors when testing the sticks singularly
Furmark: test passed with no errors (30 minutes)
hdtune: no errors

Second test group on second identical machine (Acer T650-99TZ + hdd, ram and gpu from the first machine)
prime95: rounding was 0.5, expected less than 0.4 (after 2 minutes)
memtest86: many errors whit 2 stick of ram, 0 error when testing the sticks singularly

Third test group on second and first machine (same hw except for the gpu: here I took out the HD 3650 and used the integrated gpu)
prime95: no errors (in 8 hours)
memtest86: no errors (100% passed)


Ram: 2x1gb 1Rx8 PC2-5300U 555-12 hymp112u64cp8-y5
CPU: Pentium 4 524
Obviously no overclock was made on this pc.
Obviously gpu drivers are up-to-date.

Now i'm trying to donwngrade the drivers of the GPU but I think this won't work, since the problem appear to be an incompatibility between the HD 3650 and the other hw.

Can anyone help me to solve this problem? Thanks