I thought video card is broken, so I need to change it, but that's not only problem I had.
I couldn't even install Windows 7 32 or 64bit. I got memory errors all the time.°
So I removed RAMs one by one.
What I noticed with RAMs are -
1) with 4 RAM modules I couldn't install windows I got memory errors
2) With one RAM modelue computer didn't even start, just black screen and no beep sound at begin.
3) also computer didn't started when I put two modules in slot 1 and 3.
4) I could start computer and managed to install windows with two modules in slots 2 and 4.
5) I could start windows (already installed) with all 4 modules. And it showed 8Gb RAM. But time by time I got Memory
6) Windows Memory diagnostic tool didn't show any error.
Cataclyst stops to work constantly, with all four RAMs windows explorer stops working and restarts all the time.
Sometimes I get blue screen.
Bug Check String MEMORY_MANAGEMENT
Bug Check Code 0x0000001a
Parameter 1 00000000`00041790
Parameter 2 fffffa80`0635c9a0
Parameter 3 00000000`0000ffff
Parameter 4 00000000`00000000
Caused By Driver ntoskrnl.exe
Caused By Address ntoskrnl.exe+71f00
File Description NT Kernel & System
Product Name Microsoft® Windows® Operating System
Company Microsoft Corporation
File Version 6.1.7600.16385 (win7_rtm.090713-1255)
Crash Address ntoskrnl.exe+71f00
Full Path 1 C:\Windows\Minidump\101912-14570-01.dmp
Processors Count 4
Major Version 15
Minor Version 7600
Dump File 272,408
What may cause so many problems at once?
It seems that one or even two parts are broken, most likely broken is/are -