I come to you as my last resort, please help. After restoring a system image from a recent a back up. I still have viruses. I updated Windows 7 to 10 from a free notification almost a year ago. No issues until my son a while back downloaded malicious software by clicking on the wrong download key. Since then the PC's performance has been getting continually worse.
The first thing I noticed while browsing was been redirected to websites like porn sites, Microsoft Tech support pop ups locking the browser with a tel number to call for assistance. Also far too many ads, especially flashing ads purporting to clean your PC. I have Windows Defender as an AV and it always worked fine until this happened. I continued to run scans and it initially regularly found and removed malware and as long as I now used Edge as my browser using the first page only it seemed to be OK.
My default browser had been Chrome which I now realized was fake after uninstalling the real version of Chrome. Surprise, Surprise, the Chrome shortcut still remained and I could still browse by clicking the icon. So I stopped using it. Also a Mozilla Firefox icon and browser appeared which I also felt was fake and gave me no option to uninstall either. They were probably working in the back round without me realizing it.
The final straw was when Windows defender had to be restarted manually every time. Kept stopping and always showed old definitions after reboot even after updating definitions regularly. Scanning now rarely found anything and always had errors when finished e.g. 0x800500 I think?
So, I googled for a solution for the Defender problem and the Microsoft Community recommended I use Emsisoft Emergency Kit among others to run a scan. On the first scan it found over 1000 hits, pups, but many high risk trogans etc and recommended quarantine and restart. Now it only restarts in safe mode and restoring all the quarantined items doesn't work either as some were deleted on restart and some could't be restored to there original place. I am booting from a Recovery Flash drive, so I require assistance regarding your recommended preparation guide and running FRST scan?
Any suggestions is much appreciated as otherwise I will have to reset to default Windows 7 and restore the back up which was made in Windows 10. More headaches.