How do I change the incomplete folder from its default location?? It is far too full for it to stay on the current drive and I don't want to have to reinstall on another bigger drive..

By default, the incomplete folder will be in the same parent directory as the downld folder. Change your downld location & the incomplete files will copy across to the new location for the incomplete folder during that process. Go to LW's menu bar, Tools>Options>Saving & choose a new location for the downld folder (called Shared by default) & press apply. eg: I have my downlds going to G Drive instead of C.

Another more complicated method is splitting your downlds. The incomplete folder will "follow" your Audio downld folder. See How to Change download location (click on link)

I have taken advantage of being able to set different locations for images and films (drive G) and music (drive F) but the documents and programs files still save to shared (default). Is this confusing the program? as I still have incomplete designated to C:.......

Are you sure there's still incomplete files in drive C. Check Drive F & you may find another incomplete folder there. I must say I haven't explored this option too many times, but in my experience the incomplete folder seemed to follow the Audio folder (same parent folder.) But the older incomplete folder will still be on C drive but the files will have been moved to the new location.
If not, then perhaps you may need to move another of the folders to F or G also. Or as a last resort, move the entire Shared folder to another drive, then splinter them off onto the other drives.

When I changed 'documents' to G: 'programs' changed too, and I presume this works the other way round also. Now there is a second 'incomplete' in G: so I presume its reliant on where these two folders are. For now i'm happy. Cheers for your help.

As long as it worked that's what matters. I changed just the location of documents but it didn't affect the incomplete folder or any other downld folder so ... I'm rather confused. Perhaps I need to experiment around more. lol Glad it worked for you anyway!

OSX 10.3.9 . Suggested fixes Not working for me. I formerly saved to desktop but moved the save to folder inside the drive through preferences. I trashed preferences.. I preferenced saved files to new location inside hard drive and still a new duplicate incomplete folder is recreated in old location not where The saved files go. I did hit APPLY button too.
I want this inconplete folder to move but it refuses to follow the saved to folder.

I also use OSX & it does seem to be a little different to windows. I just changed the overall downld location to another HDD. I chose a new file to downld & it went to the new incomplete folder.

I say that seems to be different to windows b/c in my trials there when changing downld location also seemed to move the actual incomplete files also.

Hmm a work around would be to move all items from the old incomplete folder to the new one whilst LW is closed. You would need to replace the downloads.dat & bak files in the new incomplete folder with those from the old incomplete folder. But LW must be closed when you do this.