encrypting my flash drive with Bit Locker File Encryption on a friend's laptop but had to pause it and remove the flash drive.  When I connected the flash drive to my own laptop (which does not have Bit Locker installed on it), I was asked to resume encryption process, which I did.  Due to the flash drive still being accessible during encryption, I deleted some file on it. The encryption process still went on after DELETING the files. But I later got a red pop-up saying  ERROR: FILE NOT FOUND  The encryption process then ended immediately.  When I REMOVED the flash drive and inserted it again it wasn't showing in My Computer. Also there was no sound as to indicate the presence of a new usb hardware.  I want to know if the flash drive has been permanently damaged , and if not how can I access the flash drive on my laptop again.?

I have not TESTED the flash drive on another computer.
I have not tested another flash drive on my laptop.
Flash Drive is 32GB SANDISK CRUZER SWITCH.SANDISK CRUZER SWITCH is often sold with a lifetime warranty.
Follow the instructions. It you can not get it to work again, contact the manufacturer.
www.sandisk.com
You never mentioned how it was encrypted...
Also you may have accidently moved the tiny switch on that UNIT that locks the drive from access...OP mentions Bitlocker
http://en.wikipedia.org/wiki/BitLocker_Drive_Encryption
It is NOT on all Windows versions.
From the above article the encryption is a form of AES.
You can also do AES from the free 7-ZIP program.
www.7-zip.org/

IMHO most users SHROUD avid using BitLocker unless they are are sure of what they are doing. For most of us,  7-ZIP can provide enough security for personal and small business use. And 7-ZIP is widely available, free, and is easy to use.