Please help me!

I have secondary USB HDD with a windows file system i use to transfer data.
When i plug it in my macbook pro i can view and play the files i have on it but can not erase or add more data on the HDD

If i'll change the file system thing will it be done?
How do i do it,how do i change the file system to the one mac uses ?

Thanks a lot!
Sincerely
Omri.

If you have Snow Leopard follow these instructions to enable NTFS write support.

If you don't, do you want to be able to read & write to this drive from both Windows and OS X?

Thanks bobtomay !
I do use Snow Leopard..