@G_String
I am not brilliant at fault finding on computers
the banking! site lets me
Found incompatibility problems with Chrome, with some programs I use,
a lot of the sites I try to get into give a certificate error
Another thing happening is I am being diverted to advertising/gaming websites from a legitimate click or menu option on a known site.
You need professional level help - - - with the computer.
I would
not be doing any banking with it until it was sorted.
There are forums where you can get the help you need. It will be a long haul. You will have to follow precise instructions and submit various logs but you will likely get it sorted out in the end. Make sure you have backups of your data before you start.
I do not have a personal recommendation but these look like somewhere to start. Pick one and stick with it.
1.
https://forums.malwarebytes.org/inde...-removal-help/
2.
Virus, Trojan, Spyware, and Malware Removal Logs Forum - BleepingComputer.com
Have a look at this thread to see what you are letting yourself in for.
https://forums.malwarebytes.org/inde...rror-in-vista/
You may well need a second computer to access the forums while you work on the problem one, or you might be lucky and not need that facility.