unable to read data from External Hard drive enclosure

I attached my old hard drive to external hard drive enclosure kit and connected to my new xp computer. Now this shows up in computer management- disk management utility. It shows correct size and also indicates how mush is free. But, how do I access the data. There is no drive letter attached to the external drive. It seems like it is partially recognizing the drive. Please advise. I don't want to format it. I want to copy files from this old drive to xp machine.