I am running across quite a few PCs (W8 and 10) who's OS seem to be corrupt. On start the circle will just keep going around. I test the HDDs and their are ok. I have a W10 install disk and a W8 repair disk. Both are bootable and give me access to the restore options and start options, none of which usually work. Given the behavior I suspect that have been infected with a virus program that is built to work on an older operating system but on W8 and 10 just messes up the OS. I don't need help fixing the computers. I just have 2 questions.
1) If you are well versed in computer repair have you run across this type of problem and in your opinion are my thoughts about some viruses and their interaction with W8 and W10 correct.
2) Could you give a link for where I can burn a bootable DVD anti virus scanner that you use and recommend. Not to expensive or free would help.