How to do a system reset without data loss?

[PKP3]

Unfortunately  I had installed a 'quick heal' antivirus package recently. Next day got a message from them to upgrade the antivirus software. I clicked ok. After few minutes, system went for a reboot. From then I am unable to go to login screen. The system restoration point I set already, is not showing up any results. Unable to uninstall the latest updates. Only option seems to be system reset as I don' want to loose data. But when I tried it, it is saying that the 'C-Drive' has no space to do reset. Can someone help me on this?

[WAWood]

@PKP3 

Sorry, but the basic fact is -- you don't!  There are different forms of system reset but in all cases, the data is overwritten and lost to Windows.

There are data recovery apps you can purchase that might be able to recover most of your personal data, but you would have to buy, download, and install them and recover the files to an external device -- like a USB stick.  If you want a list of apps, I can provide that.

[PKP3]

Thank you for the response. I was able to login by changing the start-up behavior - option no.8 - by stopping malware protection while launching windows. However, problem has not been sorted out fully. During restart, sometimes it is going to the reset / recovery menu. Don't know the actual reason. For now, I have deactivated the QH antivirus protection.