"Cleaning" Up an Old Computer? [Software].

I've had my current Computer for almost 8 years now. It's gone through several upgrades and replacements and is still in perfect condition, so I'd rather not throw it out. Instead I'm giving it away to my parents..and..I'll admit, it's going to require some.."Cleaning".

I had received this computer when I was about 12 and I'll be honest, over the years there have been things that have come and gone through this computer that I'm not too particularly proud of. Or in this case, things I'm not too eager to have plastered to the front of the fridge.

So I'll stop beating around the bush, how exactly do I cover my tracks here? A clean install of the OS is a last resort, mainly because my parents are old and I'd rather not have to go through and make everything "comfortable" for them to use again. I'd also like to refrain from wiping my HDD since it does contain a few large sized items they might like.

I'm not sure if my AV program has been set to perform back ups..is there way to check that?

I'm really open for suggestions at this point, it's embarrassing to admit, but who better to ask than the internet