Windows 7 Clean up software?

Just a question here and perhaps a suggestion that may be of help. I love to keep the computer clean and Windows 7 is very easy to use for that however I ran into a problem with AVG Computer tune up. AVG Free | Clean, Repair & Optimize Your PC | Free PC Scan and Tune Up Software | Canada I uninstalled it after I found that it wiped out all the data off of some very important excel sheets I had (thankfully I had them backed up). Tried it a few times but the data kept on being erased. I'd like a suggestion as to some sort of good reliable cleaning utility similar to AVG's tune up program. Rather not get AVG again but something else. Any ideas?