Recently I have assembled a Pc with SOFM2 ASROCK FM2A88M-HD M-ATX - FM2A88M-HD+ motherboard and cpu Amd A8 7600.
I installed Win7 Ultimate but - I don’t know if has worth - during upgrading O.S. my friend tried to plug a new hard disk added with pc turned on and the system shutted off.[/QUOTE]Here’s the problem adding a HDD when it is on will kill the system because of power surge that will most likely kill the HDD as well.
[QUOTE=umby75fg;2764812]When I tried to turn on Pc it shows the boot.mgr missing…as a profecy.
I tried to repair by installation Win 7 Cd and system worked fine ending also about 1Gb of upgrading.[/QUOTE]What would you expect when your friend did that it corrupted the installation thus there was no O/S installed or boot system installed.
[QUOTE=umby75fg;2764812]Meanwhile I was not there my friend told me that he entered into bios modifing something until I said him to stop it.
Now the system if you try to install/repair by Win7 Cd gives you the image Starting Windows session endlessly.[/QUOTE]This means your friend hosed the system and you need to start from beginning again. Your friend is no friend at this point in time. You need to reset the BIOS to default Factory to remove any changes your so-called friend did. Why are you letting the friend mess with your system? That friend has no obligation to fix anything the friend damaged.
[QUOTE=umby75fg;2764812]Even if you try to replace the hard disk the system gives you the same result.
This is very strange…because even if he modified something into bios this result is out understanding.[/QUOTE]No your friend plugging a HDD into a “ON” system most likely damaged something on the motherboard and HDD doing this bonehead move. You never plug HDD into a “ON” system do that and you can expect trouble and damaged hardware.