I’ve seen folk complain when they edit 4K and now 8K video. That’s a lot of work so it’s proper for the PC (and Windows) to be slow.
Another common complaint about slow PCs is when the owner/client has used a newer PC with faster everything and goes back to their old PC. Fix? Upgrade or replace.
Finally the real problem here is lack of information. What is this PC, what is “work?”
– Is it slow also when doing activities not related to work? Or is it always slow?
– What changed compared to when it still was fast? Or has it never been fast?
Sorry to read that. Did you already try the 8 tips from the CNET article above?
Keeping a Windows PC or laptop lean and clean can take a lot of time. If time is money for you, consider spending some money on local support or new hardware. If you have time enough, start learning.