Working drive requires Initialization on different computer

I have a Samsung HD103UJ 1TB HDD that works fine on my HP DV7 laptop connected via USB. It mounts normally and all is well. On my HP Pavilion desktop with a newly installed Windows 7 O/S, the drive can be seen in Device Manager, but when I open Disk Management, it says it needs to be initialized. I have not initialized it due to the fear of wiping out the content. I tried both USB and...