Sure, you can put Windows Defender Offline on a jump drive.
Originally Posted by kstavert
But the emphasis of my post is that you no longer have to do that ...
you can launch Defender Offline from Settings > Update and Security > Defender > Defender Offline
as described here: Defender Offline
simrick (safe mode Adwcleaner with a question about the reg entires) and Borg (tdssKiller, Rkill, possible manual reg entries removal) have offered other suggestions - it helps troubleshooting if you always follow the order of the suggestions and report the results.
When you've completed all on-demand scans and other remediation steps, run the following (both commands take a while to complete).
If there are any integrity issues reported in the results on the screen,
Launch Command Prompt (Admin)
Dism /Online /Cleanup-Image /RestoreHealth