It depends on a lot of things, so we need more background.
But, meantime, are you able to burn your DVD files to a folder on your hard drive rather than directly to a disc?
Welcome to the forum.
In addition to Steve's questions, I have one more, please:
Do you have a Stop Marker at the end of your PrE Timeline? If so, remove that, as a Stop Marker at the end, can cause the Transcode to hang at about 99%.
Let us go through the details to determine the factors involved here.
1. What version of Premiere Elements are you using and on what computer operating system is it running? Please describe your computer resources.
2. Please excuse, but I must ask, are you sure that you are using a DVD disc and not a CD disc? What brand and type disc are
you using? Have you tried another disc?
3. In the burn dialog with a check mark next to Fit Content to Available Space, what does the Quality area show for Space Required and Bitrate immediately before you hit the Burn button?
4. What is the content and duration of your slideshow....photos, how many and what pixel dimensions...video, format?
Let us start here and then decide what next.
Add On...I did not see SG's and Hunt's posts until have I had posted mine.