My suggestion:
1. Download Killdisk and 0 your hard drive. If your neighbor has already done this and is sharing off your hard drive, you are screwed until your harddrive is null.
2. Make sure your drive is 0’ed. This means all sectors are a 0. This does not mean windows has repartitioned it.
3. Reinstall Windows and start your computer over with a SECURE wifi with a password and limited access.
4. Now you can decide whether to report neighbors or not.
If you 0 your hard drive you must do it at least 3 times and that doesn’t mean the FBI still can’t figure out what has actually happened. They have a computer forensics department that can figure out what went on.