I wanted to jump in and ask a couple questions, as we might have a bit of a misunderstanding going on. We offer two encryption products, and Chetan and Anthony are both correct, but from different product perspectives.
If you are using Symantec Endpoint Encryption (SEE), Chetan basically has the right idea. I believe the drive encryption is somewhat tied into the hardware ID's etc from the system it was in originally, and it can be difficult if not impossible to recover data after a hardware failure (e.g. motherboard death). In this case, backups are your friend. You could use SEE Removable Storage to transfer files to your business partner, even if the recipient does not have SEE installed.
With Symantec Encryption Desktop (SED, formerly PGP Desktop), you can slave the drive to any othersystem that has SED installed, and attempt to access the drive to recover data. You would simply use any valid passphrase for the drive to authenticate to it.
In the case of a removable device, you can use Symantec Drive Encryption (part of the SED package) to enrypt the USB drive to a passphrase. It can then be opened on any system using SED by entering that passphrase after pluggin in the drive.
If you have encrypted files on a USB, and your business partner does not have SED, you could potentially get a trialware version for them to install to access the USB drive.
Let me know if that covers it, or if you have additional questions.