OK, I found THE solution! At least the one for me. First the problem. My Seagate Freeagent Go 500 GB hard drive not showing in Windows 7 in such a way that- you cannot open or get into it. I have a 64 bit Windows 7 installation. I tried all and everything. The drive DOES work in all other computers, on XP and Vista. So, it is exclusive to Windows 7. Many posts say to go to Computer and right click, an option called Manage, select that. Then among the choices, click on Disk Management. Once here, the hard drive does show, but no option to open exists with most people. Many solutions that worked for other people did not work for me. I do believe however, that when it shows generic and no name for a volume that we are onto something. But first what I tried that did not work. For instance, right clicking on the drive and making it Mark Partion as Active did not work. The classic fix of Change the Drive Letter and Paths did now work for me. Every solution to update the driver was focused on including downloading a Driver package diagnostic tool off Seagates website that says it branches over Winows 7 32 bit and 64 bit applications did not help me, but it did let me test the drive as being OK working order. Basically, when I tried those other solutions of changing drive letter path or of tyring to format etc., this message pops up saying something about the Device Manager being out of date, basic errors of not being able to perform that function. I even tried to reformat the drive, but on my XP computer. Restarting Device Manager, computer etc. Updating other drivers on the computer, rest at ease, it is Windows 7 folks. One thing worked finally and it pertains to the clue of when it does show in the Device Manager, it shows as a volume that is no named. You have to get it a name. Now, yes, I know, it has a name on all the other computers. OK, right click on the "no name" volume in the Device Manger. One other option showed that I finally tried and this works it out. Perhaps you will need to transfer all your data, a full copy to another hard drive. Don't worry, you can transfer it back. I had the advantage of it being basically empty. But in the Windows 7 Device Manager, there are these wonderful handy ways to organize hard drives, partitions, formatting, extending etc. But the one option we have to click on available, the magic pill- Delete Volume. Once deleted, now it will let you format it. Once you do that and IN THERE -assign it your new letter drive- and finish up and SOLUTION time. That did it for me! Hope this helps one and all who are many that are having this problem and NOWHERE could I find this answer- I came up with it with my own experimentation.
but after i tried using easeus data recovery tool on it, it stopped being detected. it doesnt even show up in disk mnagement now 
In disk management, i can see two unnamed volumes but their size doesnt match the size of the HDD. can you suggest what to do to get my data back. i dont want to lose my snaps and videos
