Yes, Windows RT is Microsoft's biggest failure. A quick search online for this tablet software program developed by Microsoft will yield a myriad of negative articles and bad reviews. With too many glitches and issues surrounding and caused by the software program, no one wants to use Windows RT, thus making it Microsoft's biggest failure.
We haven't seen much action from Microsoft in the competitive tablet industry. The presentation of Windows RT and then the birth of the Microsoft Surface RT opened the door for Microsoft to gain some real profit in that particular category. Tablets are going to become the future and the Windows RT functionality lifted some of those limitations once placed by bulky laptops and localized desktops.
I think that Microsoft has not been the same lately, especially after the retirement of Bill Gates. I do not know who is running the show in there, but someone is really messing it up, and they just do not seem like they are going to hit a home run in the near future.
I really get irritated when my tablet doesn't run like my computer. I want the ease of a computer at my fingertips. Tablets only do tablet things. Just combining the two into a perfect tablet/desktop world will solve everything. It needs to come with a keyboard, but be able to detach. It needs to be touch screen, but I need to able to use a mouse. It needs to be my computer, and my tablet.
The bugs. Oh the bugs! The TCP/IP stack bugs. The Root bugs. The Registry error bugs. The "Validation" bugs that carried into 7 too somewhat. Windows RT was not successful but by no means was it so bad that it effected what MS was all about: Their OS. Lately they've been on shaky ground with bugs and fixes... There's a reason for years people stuck with XP for business machines.