580S - options other than reformat?

i have a 580S. It has 8GB of RAM but had gotten terribly slow from what it use to be. I've done virus scans and malware scans. I've also done some registry cleaners I've see posted. In the "old days" I just did a reformat every couple years. However, I remember when I got this computer no discs came with it, but I read where that is normal now. Is there anything else I can try before reformatting? I've tried system restore, but it hasn't helped. Appreciate any suggestions!