The filesystem is not a property of the laptop, it's a property of the partition. So it's shown in the right click properties of that drive letter (that should be c:).
The picture in http://www.makeuseof.com/tag/file-system-find-runs-drives/ (about 40% down) shows it: "File system: NTFS"). Not too difficult to find out, I'd say.
As Bob said, if it happens to be FAT32, that can't contain such a big file. There are 2 solutions:
1. Make a full backup of the drive, then convert it to NTFS. http://www.sevenforums.com/tutorials/11106-convert-fat-fat32-volume-ntfs.html tells how (for Windows 7, I don't know if it's the same for Windows 8). The full backup, of course, if needed just in case something goes wrong. Then you would lose everything.
2. See if the program that you use for burning the file to Blu-ray can read the file directly from the USB-stick. Of course, it might make temporary files on the c:-drive which then might be too big also, but it''s worth a try.