I have a client and who has been receiving prompts to "Open With" when attempting to open EXE files. I have run a full scan with Malwarebytes, and found a number of viruses, which were all removed. I also downloaded and ran a script which corrected the registry to allow these files to be opened. But the problem recurred. I removed the antivirus that was in place, and installed Kaspersky, which immediately found a rootkit, which it removed after reboot. However the problem has referred yet again.
I wonder what could be the root cause of this, and how to get rid of it once and for all.
Any help would be appreciated.