Multiple BSODs in P7805u RAM issue

First of all, English is not my mother tongue so......... I ll try to do my best explanation.

Notebook Gateway FX P7805u (original hardware I didnt make any hardware change)

Processor p8400
RAM 4 Gigs 1066 (2 modules)
HD 320 gigs 7.200 rpm
9800gts nvidia 1 giga RAM
1920X1200 resolution
Vista 64 bits

I bought the notebook 3 months ago (from an old friend).....and I didnt realize this error until now. The notebook initiate properly but it gives multiple BSODs at anytime (15 minutes, 2 hours at anytime). So I format and reinstall Vista 64 bits but BSODs continued. I format ans install XP 64 bits but BSODs continued. I format and install windows 7 64 bits but BSODs continued

I tried these steps to solve problem but none of them did it:

-- I did a memtest 2 modules of RAM (apparently RAM is ok, any error at this point).

-- I Clean up RAM modules and Slots. (all clean but nothing)

NOW HERE STARTS THE AKWARD PART

-- I took out one RAM module and the Notebook works great !!!!! (None BSODs so I thought the RAM I took out or the empty slot had to be damaged or something. But once I replace the module RAM for the bad one ( I thought it was bad) The notebook works great too !!!!!!!!!!!. So I told myself it is had to be the slot but NO. I tried all options both modules of RAM are ok and Both slots works well.

I also tried a third module of RAM from a friend (same bus same RAM 2 gigs). I didnt work.

To sum up Notebook works well as long as it works with only one module of RAM.

Any idea to solve my problem???

 

1 4gig stick.

 

The memory has to work dual channel and usually is at comand rate 1T. There is a good possability the ram chips have just had it. I think dos level memtest is just 32 bits so you are not really testing all 4GB. You could try windows memory test but you said the problem is intermitent. This could be an issue as well.

If you have 2 other known good modules, you may want to try that...............

 

I will try to get a 4 gigs stick......... Its hard to get one (I mean here)

Thanks TANware, I will try to get 2 good sticks ( 2 gigs each). (This will be easier than getting one 4 gigs stick).

I didnt try to install a 32 bits system ( I know that It will not recognize all 4 gigs of Ram) but I will be happy with 3.5 gigs of RAM. Now I only have 2 gigs working

 

I decided to buy a 4 gigs stick.........but a question? Does the notebook support a 1333 mhz RAM?? . Because there is no diference between 1066 and 1333 I mean price.

1066 = 90 $ (4 gigs)
1333 = 95 $ (4 gigs)

 

it will run 1333 memory as 1066..................

 

Ok Thanks TanWare........ So it doesnt matter........... I knew that but I wanted to be sure.......

 

By The way, I installed Windows XP sp3 32 bits, it only recognized 3 gigs. That was predictible. But a BSOD after 5 minutes . Monday I will buy the 4 Gigs stick. Wish me luck