to keep my computer running as fast as new, i keep the clutter down with ccleaner, with an occasional run of windows enhanced disk
cleaner (to improve it go to run, type 'cmd,' then right click on the cmd that pops up to 'run as administrator' at the prompt that appears, type: cleanmgr/sagerun:1 ... this will give you many more cleaning options.) i also use wise registry cleaner. i just installed an old favorite, tweaknow powerpack, has a good registry cleaner in it. Soluto speeds up my boot, it's free also, i run system file checker (scans the integrity of all protected Windows 7 system files and replaces the incorrect versions with the correct versions, if possible. Go to run, type 'cmd,' then right click on the cmd that pops up to 'run as administrator.'
At the 'c:' prompt type: sfc /scannow then press "Enter") and checkdisk while i sleep, the "r" flag takes a while at first (lists and corrects errors on restart: go to run, type 'cmd,' at the c: prompt, type chkdsk /f to fix errors or type chkdsk /r to check every sector on the hard drive and recover any readable information as well, which takes a long time, but it's worth it, on older hard drives, it will flag all of the bad sectors it finds, will route the software around them, which will stop windows from freezing up on those bad sectors.