If only the motherboard is broken, you can replace the motherboard and connect it to the hard disk at home. However, as long as the documents in you are not confidential or top secret, the regular computer maintenance department will not disclose your documents. However, your hard disk may also be damaged, because the motherboard may be damaged when it burns. If the hard disk is damaged, you may need to ask the data recovery company for help.

In addition, I suggest that you back up your files, because the system usually formats drive C. In order to avoid data loss, you can back up your files with a U disk, or you can hang your hard disk on another computer to back up your data, such as your thesis.

Good luck. The general maintenance department can change it for you then. It won't take long, half an hour is enough. If there is no stock, it depends on your location.