Leak: HP's iPad Challenger Coming in October Device apparently runs on Windows 2 comments Comments A file photo of the iPad. H-P looks to be rolling out a competitor next month. (AP Photo/Marcio Jose Sanchez, FILE) (User Submitted) – According to a tipster who provided hands-on photos, HP's "Slate 500" tablet is coming at the end of October, writes Dan Ackerman at CNET. This potential iPad rival surprisingly runs Windows 7, instead of Android or Palm's WebOS. On the heels of Samsung's Galaxy Tab and BlackBerry's PlayBook, the tablet/slate field is starting to look a little crowded.