No need to re-import, certainly!!
To make sure you are aware, it is easy to move all of your settings and your Library (Media Center's database) to the new computer:
http://wiki.jriver.com/index.php/Library_BackupThe easiest thing would be to:
1. Make a Library Backup on the old computer.
2. Copy all of the files from the old computer to the new computer and put them in the exact same "place" (same drive letter and path) as they exist now on the old computer.
3. Install MC on the new computer and get it licensed.
4. Copy the backup zip file you made in step 1 over to the new computer and restore it to your new copy of MC.
This will make the new copy of MC match exactly, including all settings and everything, the old copy. As long as the files are there in the same place they were originally, you're done.
If you cannot copy them all over using the exact same path (maybe they used to be on C but now won't all fit on C), do exactly the same thing, but copy them to whatever new drive you need to copy them to, and then do the exact same steps with a fifth additional step of:
5. Select all of the files in the new copy of Media Center (they'll all be "broken" because they'll point to the wrong path) and do:
Right-Click > Library Tools > Rename, Move, and Copy FilesThen use
Find & Replace mode in the tool to fix the paths to point to the files where they actually live (if you're just switching drives, but the directory structure and filenames are unchanged, this should be easy).