Error when deleting files from external HD

Hi there,

I bought my first mac (Aluminum Macbook 2.0GHz) a few days ago. So far so good. The learning curve wasn't as steep as imagined.

There's an error I haven't been able to resolve. I transferred all my files to my external hard drive. A 500GB Western Digital HD. When I try to delete files from the external HD I first get this message:

"The item "whateveri'mtryingto.delete" will be deleted immediately
Are you sure you want to continue?"

I click continue and I get this:
"Sorry, the operation could not be completed because an unexpected error occurred.
(Error code -61)"

Your help will be much appreciated.

 

Thanks for pointing out the formatting. I was able to convert it to FAT32. Now I need to move all my files, which are spread out across three computers, back on the external hard drive. Takes a while but now my external hard drive goes both ways. Thanks again,

John