Follow these steps to reinstall Minecraft on your Windows PC.
1. Avoid deleting the launcher, which is the.EXE file. It would be used to download the Minecraft files again when re-installing it.
2. Press Windows + R and then type "%appdata%." Now press enter on your keyboard to open the roaming folder.
3. Double-click on the Minecraft folder to open it. Locate the ".saves" folder, and copy it to another location so as to get back your saved worlds after you reinstall.
4. Go back to the roaming folder and delete the Minecraft folder to uninstall Minecraft from your PC.
5. Download the Minecraft launcher from minecraft.net if you don't have it on your system again. Then launch it. This will make Minecraft to be installed back into your computer after some minutes.
6. Close Minecraft after it must have finished launching. Then go and open the Minecraft folder, and copy the saved folder back into it. This will help you to continue your game from where you stopped.
