You need to tell us a little more about your external HDD, size & model #, adapter type (USB, Firewire, eSATA), etc.
If it is a USB as most are now, you should just have to connect it with the appropriate cable and power it up. If it hasn't been partitioned and formatted, you need to go to Computer Management, then Disk Management, and click on the Drive in the lower graphical area.
You need to first Initialize the drive, which adds the Disk Type (Basic or Dynamic), Disk Signature, & End of Sector Marker (Signature Word). Then Partition the drive into a single, or a couple separate partitions depending you it's size and intented use, and finally format it with NTFS. In that process you can assign it a Drive letter, and Volume friendly Name.
Thanks!! but it never worked, I have a Toshiba USB 2.o 500 GB external hard drive. I try to quick format it. and all that happen is it delete all my files, still not formatted i rename the drive. it cant open it seems like my computers do not recognize it some message saying windows cannot open it am so confused i need all the help i can please
Is this a new external HDD, or an older on you moved to a new computer to use?
Please go to Disk Management - right click My Computer, Manage, Computer management, in the lower left area click on Disk Management. With the external drive connected, please upload a screenshot of the Disk Management dialog box showing both the upper and lower graphical areas.
Can use photobucket or imageshack for this. Post the image with your response so we can see exactly how the OS is recognizing this external HDD and what the Disk and Volume parameters are.