The image clearly states that your system is suspected to be infected with a master boot rootkit.
What is Master Boot Record ?
Master boot record is the information present in the first sector of any hard disk. It contains the information regarding how and where the Operating system is located in the hard disk so that it can be booted in the RAM.
Solution
The only solution to make your PC completely free from boot sector rootkit is to reinstall your OS from scratch and take the necessary backup before that.
Now, if you plan to reinstall your OS from scratch, I would first advise you to try and run these below portable scanner and see if they are able to detect and remove the rootkit.
* Bitdefender Rootkit Remover (http://download.bitdefender.com/removal_tools/BootkitRemoval_x64.exe)
* Malwarebytes Anti Rootkit (https://data-cdn.mbamupdates.com/web/mbar-1.10.3.1001.exe)
* Avast Anti Rootkit (http://public.avast.com/~gmerek/aswMBR.exe)
* Download and run a scan with Kaspersky Virus Removal Tool (https://devbuilds.s.kaspersky-labs.com/devbuilds/KVRT/latest/full/KVRT.exe). Make sure you checkmark System Memory, Startup Objects, Boot Sectors & System Drive before running a scan.
But as far as I know, since it is the master boot record rootkit, if it does not gets detected or removed by above tools also, you will have to reinstall your OS from scratch.
Regards
