Can I Reset A External Hardrive

[rph105]

was backin up using time machine and my brother unplugged the external hd, now time machine doesnt recognize it to bacup, is there a way i can reset the hardrive to its factory settings???

 

[superleccy]

Applications > Utilities > Disk Utility.

If you can see it in Disk Utility, reformat ("Erase") it. Choose "Mac OS Extended (Journaled)" as the format.

SL

EDIT: Obviously you will loose all the data on your hard drive.