Computer won't start after a scan and supressing of malwares

[Dagrumpy]

Hello
So here is my problem :
I was to a friend's house, and her computer had severals problems, with malwares and all. So I downloaded Rogue killer on her computer, scanned, then supressed all that has been found.

After that, Rogue killer needed a restart from the computer, to finish the suppression.

But when it restarted, it just make this message : Operating system not found ( with some other things at the top but .. )

And it's always like this, it won't restart.
What is the problem here ?

[Curson]

Hi Dagrumpy,

Welcome to Adlice.com Forum.

Which operating system is your friend's computer running ?
I guess a critical system file was infected and its removal caused the inability to boot.

Regards.