Computer Help and Support

Javascript is built into all web browsers. No need to update besides the usual monthly updates.

"Java" is a different language that is not used very often except for some applications. I doubt you need it. Don't click any messages. Run a malware scan with two different programs, like Windows Defender and Malwarebytes.

If that doesn't cure things, talk to us again, but do NOT click any messages.

ETA: Sorry, middle of the night reading is not the best for me, ugh. I missed the part where you did click the prompt.

Go into your Control Panel, find the Java (if it's there, hopefully it is), and uninstall it. Reboot. I would still do the malware scan with two different programs.