I keep getting pop ups from the above to repair 'problems' with my PC. Norton says they are a respected product. I did run it about a couple of months ago and they reported >1000 faults that needed attention. I am a Norton customer and always get a clean report from them. I suspect they are odds and s*ds of programs which are no longer required to process information, which may or may not be a problem. Norton are obviously not worried. It is relatively cheap to purchase, £6ish.
I'm wholly with Hans on this one. Reimage is a waste of time as, indeed, are most similar products. The general advice (both here and in the technical press) is to steer well clear of software which promises to 'clean' your computer.
However, if you're determined to try something anyway, there's just one program that's well-regarded (and frequently recommended, both here and in the technical press). It's the free version of CCleaner:
https://www.piriform.com/ccleaner/download