ok, voici ce que le logiciel me dit :
System Information (local)
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computer name: ELFENOIR-PC
windows version: Windows 7 , 6.1, build: 7600
windows dir: C:\Windows
CPU: GenuineIntel Intel(R) Core(TM) i5 CPU 750 @ 2.67GHz Intel586, level: 6
4 logical processors, active mask: 15
RAM: 3211845632 total
VM: 2147352576, free: 1971941376
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Crash Dump Analysis
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Crash dump directory: C:\Windows\Minidump
Crash dumps are enabled on your computer.
No valid crash dumps have been found on your computer
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Conclusion
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Crash dumps are enabled but no valid crash dumps have been found. It may be that there are problems which prevent crash dumps from being written out. Check out the following article for possible causes: If crash dumps are not written out.
In case your computer does experience sudden reboots it is likely these are caused by malfunctioning hardware, power failure or a thermal issue. To troubleshoot a thermal issue, check the temperature using your BIOS setup program, check for dust in CPU and motherboard fans and if your computer is portable make sure it's located on a hard surface. Otherwise it's suggested you contact the support department of the manufacturer of your system or test your system with a memory test utility for further investigation.
Check out the following articles for more information: Troubleshooting sudden resets and shut downs.
Read the topic general suggestions for troubleshooting system crashes for more information.
Note that it's not always possible to state with certainty whether a reported driver is actually responsible for crashing your system or that the root cause is in another module. Nonetheless it's suggested you look for updates for the products that these drivers belong to and regularly visit Windows update or enable automatic updates for Windows. In case a piece of malfunctioning hardware is causing trouble, a search with Google on the bug check errors together with the model name and brand of your computer may help you investigate this further.
trad, please, parceque là, moi.....
merci à celui ou celle qui a déplacé mon sujet au bon endroit! 
(selon le rapport, ce qui ne veut pas dire que tu n'as rien)