[Krusty1231]

Go to your admincp. Scroll down to avatars - open it - look at "user picture storage type". You should be able to see the changes needed right there!

These directions taken from here:

Instructions:
1. Go to your vBulletin Admin Control Panel -> Avatars -> User Picture Storage Type
2. By default, vBulletin already provides you the directories needed to store the files, and all you have to do is set the permissions of each directory to 777.
3. Login to your vBulletin root via File Transfer protocol client and find the “customavatars” "customprofilepics" and "signaturepics"
4. Set all the 3 directories file permission to "777"
5. Go back to the "User Picture Storage Type" and click "Go"
6. Click "Go" again.
7. Congrats, you’ve successfully moved your avatars, profile, and signature pictures to the filesystem.