Windows 7 asking to format my 1TB passport essential SE USB 3.0

I have tried it in several windows 7 pc’s but the same message pops out everytime “You need to format the disk in drive G: before you can use it Do you want to format it?”… I have around 800 GB of stuff which i need in it. What should i do?

P.S. The drive opens normally in ubuntu.

You can backup all data in ubuntu and reformat or use a recovery software in windows

the drive partition is corrupted


And what if, after seeing this message a few times, it no longer shows it at all anymore?

Now when I plug in my drive the computer (no matter what computer I try) keeps just searching for the data on the drive and finds nothing. 

There is a lot of VERY valuable info on this drive

Try booting from a Linux Live CD or some recovery software. Has the drive been used on different OS like XP? There is probably something corrupt. Does the drive still show in Disk Management and what does it say?