Windows Secrets reports: "Microsoft won’t tell you this, but you can do a fast, nondestructive, in-place, total reinstall of Windows 7 without damaging your user accounts, data, installed programs, or system drivers.
That means you may never have to do a full, from-scratch reinstall again, even when your system is misbehaving so badly that a full reformat-and-reinstall seems the only answer!
As I’m sure you know all too well, from-scratch reinstalls are ordeals. They take hours. And when a reinstall is done, you still have to recreate all your settings, reinstall all your software, and so on. It can take days to fully recover from a total reformat/reinstall."
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