As a precaution you should start a hard drive checking program like CheckDisk, Norton Disk Doktor, ScanDisk or something similar. If these programs should show you defective sectors or clusters, you should turn your computer off immediately and discontinue further work. It could already be the case that small surface damage already exists which will be made worse by using data recovery programs.

If the test program does not show any defects, then you can use a data recovery program to recover your data.