Missing Gigs After Installation?

Hi. I have a new question about something that we discussed here awhile back, so I will just post in this thread. I took the advice above and ordered an external enclosure for my TB hard drive. It turned on and connected alright, but it only gave me the option of reformatting. This is all well and good, but the whole reason that I wanted the enclosure was to get my data off the disk. I talked to the tech support at the company that sold them, and was told there's no way around that with their enclosures. This is important to me, so I wondered if anyone here knows of any other way to retrieve data from a TB drive. Thanks for any help or suggestions.

Thanks whs. I forgot to mention it but I really don't have a desktop that would handle a TB drive. I've just been buying laptops for the last few years. Even if I did put it in a comp, wouldn't I still have to reformat it?