Windows 7 this is incredible i had bsod on my sony laptop and now sony replaced it and new one also has bsod

[johnfortis]

My previous sony vaio(almost new)started to get bsod

*fact> that this one got a replacement memory before it was a 4gb memory now its 6gb.

Soo they did a system restore because sony couldn't find anything in software problems. So after the recovery it still had bsod, they changed the hard disk drive 2 times and I used it in front of them for 2 minutes and what happens? Bsod. For the situation they replaced it with a new laptop sony vaio s series very good computer. It was 4gb so when the passed the 4gb memory that I bought in the beginning to the new one it now has 8gb memory. When I got home I put my external hard disk and during some windows updates and vaio updates it happened again bsod. I was pi**ed off. Soo I took it to sony AGAIN they concluded it was a faulty memory. They changed it free of cost for a new one when I get home what do I encounter the BSOD. there are no programs installed in the computer except factory ones and panda antvirus and its original not cracked or anything.
My theories (but I'm not such an expert) are:
1. The "faulty" memory(now we don't know if t was faulty or not) damaged my old and new computer somehow don't onow
2. My external hard disk may be causing bsod but it very weird cause I didn't install.anything from it and I frequently scan it completely. But anythng is possible
3. I have bad luck
for last I have done memory diagnostics and it appears completely good. The cpu diagnostics was good. If I use the computer it rapidly gives a bsod radomly sometimes in first 5 minutes and may even take hours. Please help me I need to do a research presentation in december in a hotel from university and I'm very in need of my computer.

 

[johnfortis]

I got the computer... For what they showed me as in documentation, appears as if I had used a generic volume on the computer, they were saying it was the external drive, but we did not discuss that, they wanted the explanation of other downloaded things, such as whatwe used, sf diagnostics, microsoft essentials and malware removal all those stuff.

They re-installed the operative system, but without something...the extra memory that was added. The thing is that FOR NOW the computer has been in use for about 3 hours and no problem with BSOD. I hope this was the problem, they handed me the memory.

The name of the virus I will get it tomorrow I hope, because I handled everything with the manager and the technician was free and is the only one who knows this name, hope she wrote it down somewhere.
And I am very appreciated by your support,
Best Regards,
John Fortis