Greetings!
Recently someone used my computer and ended up installing some adware/malware nonsense. Upsetting? YES! But I did what I usually do once in awhile and attempted to reinstall Windows 7. I succeeded. Sort of. I don't think I totally formatted the hard drive right. I got to a point where it told me all my old data will be saved in a windows.old folder. I don't want ANYTHING saved anymore. I want a totally fresh machine. My c: drive is even showing there's still stuff on there. I'm able to use everything normally again but I'm now noticing spikes in my CPU usage also and I feel like there's still some malicious stuff running in the background..
I'm hoping someone can walk me through completely reinstalling Windows and properly formatting. I have my systems disks so it shouldn't be that hard 
Thank you so much for your time!