If this is one of your standard non RAID drives (or a drive from a RAID 1 array) then you need to read the 'Data Recovery' sticky post above this.
You must realise that the drive will be formatted as a Linux Ext3/4 drive and is therefore not readable by windows unless you have an installable file system driver installed or a program that will read the Linux drive format.
If you have a Linux computer then there should be no problems at all. We have used a live linux CD booted computer to recover data from a RAID 1 array disk and copy it to a USB drive without problems, although it is rather slow.