KB3000850 & KB2976978 are optional, non-security updates (yes, even though they may be offered as Important updates). Feel free to hide one or both of them. [1]
• HOW TO Hide an Update or Restore a Hidden Update (good for Win8, too)
http://www.sevenforums.com/tutorials/24376-windows-update-hide-restore-hidden-updates.html
The above notwithstanding & assuming Win8.1 64-bit...
Please answer each of the following [admittedly tedious] diagnostic questions in a correspondingly-numbered list in your very next reply, preferably without quoting this post:
1a. When (approx. date) did you purchase the computer?
1b. Did the computer come with Win8 (or Win8.1) preinstalled, did you do a clean install of Win8 (or Win8.1), or did you upgrade a (e.g., Win7) computer to Win8?
1c. Assuming you started with Win8 => When (approx. date) was Win8.1 installed?
- What is the full name of your currently-installed third-party anti-virus application or security suite (i.e., not Windows Defender!), if any, and when (approx. date) does your current subscription(if any)expire?
- What third-party anti-malware applications (i.e., not Windows Defender!) are installed, if any? What third-party firewall, if any?
- Has a(nother) Norton application or a McAfee application EVER been installed on the computer since you bought it?
- Did a Norton free-trial or a McAfee free-trial [pick one] come preinstalled on the computer when you bought it? (Doesn't matter if you never used or Activated it.)
6a. Is KB3034344, KB3058515, KB3059317 and/or KB3057839 listed in Installed Updates (not Update History)? [2]
6b. How about KB3035583 and/or KB3044374?
7a. What Update Version & KB number are displayed in the second line of text in IE11's Help | About [Alt+H+A] tab; e.g., Update Version: 11.0.54 (KB1231231) ?
7b. Is Firefox, Chrome or any other alternate browser installed?
- Is Adobe Flash Player v18.0.0.194 for Internet Explorer installed? TEST HERE USING INTERNET EXPLORER ONLY! => http://www.adobe.com/software/flash/about/
- Are you in the habit of using "Registry cleaners" (e.g., Registry Mechanic; System Mechanic; RegCure; RegClean Pro; Advanced SystemCare; Registry Booster; McAfee QuickClean; Glary Utilities; AVG PC TuneUp; Norton Registry Cleaner; PCTools Optimiser; SpeedUpMyPC; PC Doctor; TuneUp Utilities; WinMaximizer; WinSweeper; Comodo System Cleaner; Advanced System Optimizer; CCleaner's Registry Cleaner component)?
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[1] However, KB2976978 is one (1) of the three (3) prerequisites updates you'll need in order for the Free Win10 Upgrade to be offered to your computer later this year so you may not want to hide it.
[2] Control Panel | Programs and Features | View installed updates (in left-hand menu)