Note: Save a copy of your wallet.dat. This is very important. So make copies of it.

First you go to "roaming" folder. From your keyboard press Windows logo + R.
Then look for the "rain" folder. There you can find wallet.dat, save a copy (or copies) of it into another directory.

After you've done that, you can now delete that "rain folder".
Go to where you put the condensation-qt.exe and run it again.

After you've run it, you close the wallet.
Then you go again to "roaming" folder.
Next, go to "rain" folder and replace the wallet.dat with the old wallet.dat file that you've saved previously.

After doing all of that, open your wallet and let it synch with the network.