laptop freezes and screen turns black

Hello and welcome ahmedmosaad mate I am wondering where you got this machine from because it does not have a correct copy of Windows installed in it the build should read 7601 SP1 the CODE that is attached is showing it to be 7600. Now while this was the original build the SP1 was added later to fix the bugs etc. There are a lot of counterfeit copies for sale by the unscrupulous so hence why I ask.

The dump files contain some issues with your security AV - Avast too further analysis will not run again prompting me to believe the copy of Windows is not genuine.

Code:

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*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
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Use !analyze -v to get detailed debugging information.
BugCheck D1, {84a4, 2, 1, 87f35188}
Unable to load image \SystemRoot\system32\drivers\aswStm.sys, Win32 error 0n2
*** WARNING: Unable to verify timestamp for aswStm.sys
*** ERROR: Module load completed but symbols could not be loaded for aswStm.sys

Code:

System Information
------------------
Time of this report: 10/3/2015, 05:17:11
       Machine name: MOSAAD-PC
   Operating System: Windows 7 Home Premium 32-bit (6.1, Build 7600) (7600.win7_gdr.110408-1633)
           Language: Arabic (Regional Setting: Arabic)
System Manufacturer: Dell Inc.
       System Model: Latitude E5500                  
               BIOS: Phoenix ROM BIOS PLUS Version 1.10 A15
          Processor: Intel(R) Core(TM)2 Duo CPU     T7250  @ 2.00GHz (2 CPUs), ~2.0GHz
             Memory: 2048MB RAM
Available OS Memory: 2004MB RAM
          Page File: 1372MB used, 2634MB available
        Windows Dir: C:\Windows
    DirectX Version: DirectX 11
DX Setup Parameters: Not found
   User DPI Setting: Using System DPI
 System DPI Setting: 96 DPI (100 percent)
    DWM DPI Scaling: Disabled
     DxDiag Version: 6.01.7600.16385 32bit Unicode