You can do a repair install as long as you have the right type of windows disc. A disc that is a recovery disc from the big manufacturers won't work, needs to be a microsoft produced disc usually. The other ones restore to factory condition, bloatware and all, and don't have the option of the repair install. If you can try it, your data is not lost, however, it's always a good thing to back it up just in case. Always good to be backed up.
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