Hi Christine, & Welcome to Tom's Hardware!
First of all, don't do anything, or anything more to the LaCie until all the details are known.
What's the model # of the ext LaCie, and how it is connected to a host computer, USB, SATA, Firewire?
Also how long ago was your data transferred to this drive?
What's the make/model of your "old" laptop, running Win-XP or more recent, & do you have access to a recent desktop running Win-7 or Vista
Last, did you "format" the drive when prompted, or just asking now?
That will get the info for someone to give you the best advice going forward.