Can't mount the disk with Acronis Recovery Expert

Hello !

One of my friends gave me his old 2.5" hdd from his previous laptop with the hope that I can extract some data in it. So I downloaded the trial version of Acronis DD 11.  

I've plugged the hdd into an external SATA>USB adapter and Windows doesn't want to mount it.

In Disk Management it says "Unreadable" and no action is possible.

In Acronis I get what you can see in the following screenshot :

http://img194.imageshack.us/img194/7149/44443272.png

So the disk is labelled as "Healthy (Active)" but the problem is, it is constantly mounted and unmounted. In other words I can't do anything because the hdd stays mounted in Acronis or Windows for about 1 or 2 seconds and then goes back to unmounted and unlisted until 1 or 2 minutes and again for a permanent cycle.

In this screenshot here is the disk mounted by Windows (F:) for about 2 sec:

http://img692.imageshack.us/img692/6291/53393467.png

I don't know what am I supposed to do now and how to manage this.

I've switched on Ubuntu and it said that there was a NTFS error while the disk was mounting, and this error can be fixed by doing a chkdsk on the disk, but I can't because I don't have enough time to do something.

Does anybody has an idea?

Thank you so much in advance :)

D.