Under no circumstances should you contemplate reinstalling the OS anywhere when you have vulnerable data. The hard drive is seldom a "safe" place for any data, it belongs on at least two verified backup copies off the computer before it can be considered as "safe".
If you believe that backing up will be a pain, then consider the "pain" if the data is lost.
If you believe that backing up will be a pain, then consider the "pain" if the data is lost.