Ayuda pantallazo azul y reinicios constantes

Hola, a ver si me puede ayudar, creo que es problema de hardware, pero no estoy seguro.
Tengo un pc a 64bits con vista, que me iba funcionando más o menos bien, hasta que de un tiempo para acá al rato de estar encendido me sale una pantalla azul y se reinicia.
El pc lo usa mi padre habitualmente, y comenta que no ha instalado recientemente ningún dispositivo nuevo.
La cuestión es que después de buscar información y no saber solucionarlo, me decidí a cambiar el disco duro por uno mío, formateándolo e instalando Windows 7 instalé los drivers correctos de la gráfica y lo demás lo dejé como los detectaba.... Pero mientras le estaba instalando algunos programas, Zás, de nuevo el error!
leyendo en algunos hilos de foros, he visto que piden muchas veces una serie de información, que no sé si corectamente he ido sacando con:
Debugging tools for windows
y
bluescreenview
pego para ver si me puedes ayudar.
Decir que hice un test de memoria y otro de tarjeta gráfica con programas chequeadores de errores, y no me dió error...
Este es el pantallazo azul:
http://s2.subirimagenes.com/fotos/previo/thump_6630399captura-pantalla-azu.jpg"]http://s2.subirimagenes.com/fotos/previo/thump_6630399captura-pantalla-azu.jpg[/URL]
Mensajes con el bluescreenview:
http://s3.subirimagenes.com:81/otros/previo/thump_6630353error-02-bs.jpg"]http://s3.subirimagenes.com:81/otros/previo/thump_6630353error-02-bs.jpg[/URL]
http://s2.subirimagenes.com/fotos/previo/thump_6630399captura-pantalla-azu.jpg"]http://s2.subirimagenes.com/fotos/previo/thump_6630399captura-pantalla-azu.jpg[/URL]
Mensaje del Debugging tools for windows
Microsoft (R) Windows Debugger Version 6.11.0001.404 X86
Copyright (c) Microsoft Corporation. All rights reserved.
Loading Dump File [C:\Windows\Minidump\070611-25942-01.dmp]
Mini Kernel Dump File: Only registers and stack trace are available
Symbol search path is: *** Invalid ***
****************************************************************************
* Symbol loading may be unreliable without a symbol search path. *
* Use .symfix to have the debugger choose a symbol path. *
* After setting your symbol path, use .reload to refresh symbol locations. *
****************************************************************************
Executable search path is:
*********************************************************************
* Symbols can not be loaded because symbol path is not initialized. *
* *
* The Symbol Path can be set by: *
* using the _NT_SYMBOL_PATH environment variable. *
* using the -y <symbol_path> argument when starting the debugger. *
* using .sympath and .sympath+ *
*********************************************************************
Unable to load image \SystemRoot\system32\ntoskrnl.exe, Win32 error 0n2
*** ERROR: Module load completed but symbols could not be loaded for ntoskrnl.exe
Windows 7 Kernel Version 7600 MP (4 procs) Free x64
Product: WinNt, suite: TerminalServer SingleUserTS
Built by: 7600.16385.amd64fre.win7_rtm.090713-1255
Machine Name:
Kernel base = 0xfffff800`02819000 PsLoadedModuleList = 0xfffff800`02a56e50
Debug session time: Wed Jul 6 20:11:56.680 2011 (GMT+2)
System Uptime: 0 days 0:28:21.942
*********************************************************************
* Symbols can not be loaded because symbol path is not initialized. *
* *
* The Symbol Path can be set by: *
* using the _NT_SYMBOL_PATH environment variable. *
* using the -y <symbol_path> argument when starting the debugger. *
* using .sympath and .sympath+ *
*********************************************************************
Unable to load image \SystemRoot\system32\ntoskrnl.exe, Win32 error 0n2
*** ERROR: Module load completed but symbols could not be loaded for ntoskrnl.exe
Loading Kernel Symbols
...............................................................
................................................................
.........................
Loading User Symbols
Loading unloaded module list
.....
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************
Use !analyze -v to get detailed debugging information.
BugCheck 3B, {c0000005, fffff9600018d025, fffff88008a76f90, 0}
Unable to load image \SystemRoot\System32\win32k.sys, Win32 error 0n2
*** WARNING: Unable to verify timestamp for win32k.sys
*** ERROR: Module load completed but symbols could not be loaded for win32k.sys
***** Kernel symbols are WRONG. Please fix symbols to do analysis.
*************************************************************************
*** ***
*** ***
*** Your debugger is not using the correct symbols ***
*** ***
*** In order for this command to work properly, your symbol path ***
*** must point to .pdb files that have full type information. ***
*** ***
*** Certain .pdb files (such as the public OS symbols) do not ***
*** contain the required information. Contact the group that ***
*** provided you with these symbols if you need this command to ***
*** work. ***
*** ***
*** Type referenced: nt!_KPRCB ***
*** ***
*************************************************************************
*************************************************************************
*** ***
*** ***
*** Your debugger is not using the correct symbols ***
*** ***
*** In order for this command to work properly, your symbol path ***
*** must point to .pdb files that have full type information. ***
*** ***
*** Certain .pdb files (such as the public OS symbols) do not ***
*** contain the required information. Contact the group that ***
*** provided you with these symbols if you need this command to ***
*** work. ***
*** ***
*** Type referenced: nt!KPRCB ***
*** ***
*************************************************************************
*************************************************************************
*** ***
*** ***
*** Your debugger is not using the correct symbols ***
*** ***
*** In order for this command to work properly, your symbol path ***
*** must point to .pdb files that have full type information. ***
*** ***
*** Certain .pdb files (such as the public OS symbols) do not ***
*** contain the required information. Contact the group that ***
*** provided you with these symbols if you need this command to ***
*** work. ***
*** ***
*** Type referenced: nt!_KPRCB ***
*** ***
*************************************************************************
*************************************************************************
*** ***
*** ***
*** Your debugger is not using the correct symbols ***
*** ***
*** In order for this command to work properly, your symbol path ***
*** must point to .pdb files that have full type information. ***
*** ***
*** Certain .pdb files (such as the public OS symbols) do not ***
*** contain the required information. Contact the...