In the Old Days of Win 3.1, Win 98 (especially), and XP, it was desirable every 2 years to copy off your files, reformat the C Drive, and then re-install the O/S. That used to clear out the clogged arteries and remove all the extraneous programs that somehow weedled their way into the computer.
I have a nice Samsung laptop running Win 7 64 Bit with 6 Gig of RAM and a hard drive big enough to hold the World. It was incredibly fast and did everything I needed for my business. Then about a year ago a fight between AVG and Rapport trashed the whole thing. Fortunately you guys got me out of the cr*p and it ran again - but it was never quite the same in performance terms.
Now I have retired and I don't have to be connected 24/7 or fend off a daily stream of emails. I can take a breath and review the computer operation. I'm getting windows (in Google) opening slowly, and quite a few 'not responding' delays. It's time for an old fashioned clearout. (I am very careful about downloading stuff - always going for Advanced etc so I don't have a crop of toolbars etc). Cleanups are done by Adaware, CCleaner, Spybot etc.
I have a drive in a caddy and have copied over all my important stuff. The problem now is how to do the spring clean. Two ways I can think of -
Find the 'Reset Button' so that it switches the comp back to where it was when I bought it. That might not work though because I had to use a downloaded iso after the crash to get Win 7 running again. I can then use something like Defraggler to wipe the rest of the drive before reloading everything.
Remove the C drive, pop in my caddy (connected to my spare Acer laptop), and reformat it. The problem then is I don't have a copy of Win 7 (in physical form) so its back to an iso.
Back to factory settings would be my choice if it's on the HDD - avoids any problems with type specific drivers. I'm about to do exactly that with my 4 yr old W7 for the same reasons of slowdown (despite all the usual housekeeping).