Now, go back to that HP support page. Leave a reply on that old forum thread. Post the working link. Someone else, years from now, will find their own Sleekbook in a closet. And they will find your breadcrumbs.
The official site has moved on. Your machine is "End of Life." HP has left it to rot in the digital rain. The first lesson of deep driver hunting: Corporations have no memory. hp pavilion sleekbook 15-b003tu drivers download
You find an archive.org snapshot of HP’s FTP server from 2014. The folders are raw, unlisted. You scroll through thousands of filenames. Then you see it: sp61384.exe . The description in a readme file: "Realtek Audio Driver for HP Pavilion Sleekbook 15-b003tu – Windows 8.0." Now, go back to that HP support page