Has a tendency to overdue the AV scans, Malware Scans and CCleaner Scans.
A good place to start. Update and run the active AV.
When done download, update and run full scan with Malwarebytes.
Might as well leave Mbam on his lappy as it would appear they will need it often.
It is an on demand scanner so won't interfere with the active AV. Run Windows Disk Cleanup as Administrator first and get rid of all the internet Temp files etc.
That helps a lot. There is always unwanted junk in there if it builds up over weeks.