Cannot install/uninstall .NET Framework 3.5.1

Question

Can't install/uninstall .NET Framework 3.5.1 using "Turn Windows features on/off". Everytime when i'm trying to do this, i get the message below.

I already tried to use "sfc /scannow" and "NetFxRepairTool", both with no result.

Answer 1

You do not install or uninstall applications via Turn Windows features on and off, you enable (turn on) or disable (turn off) them.

Are you telling us that you cannot enable .NET Framework 3.5.1 or...?

Is a (security) update for .NET Framework 3.5.1 involved somehow and if not, how does this pertain to Windows Update functionality?

Answer 2

Are you telling us that you cannot enable .NET Framework 3.5.1

Yes, i cannot enable or disable it and that is the problem.

how does this pertain to Windows Update functionality?

I chose "Windows Update" because i din't find better category for my problem.

Answer 3

.NET Framework Setup Verification Tool User's Guide

http://blogs.msdn.com/b/astebner/archive/2008/10/13/8999004.aspx

.NET Framework Cleanup Tool:

http://blogs.msdn.com/b/astebner/archive/2008/08/28/8904493.aspx

Answer 4

Assuming Win7 (64-bit) SP1...

Please answer each of the following [admittedly tedious] diagnostic questions in a correspondingly-numbered list in your very next reply, preferably without quoting my post:

1a. When (approx. date) did you purchase the computer?

1b. Did Win7 64-bit come preinstalled on the computer when you bought it, did you do a clean install of Win7, or did you upgrade the computer to Win7?

1c. Is this a sudden, new problem or...?

2. What is the full name of your installed anti-virus application or security suite and when (approx. date) does your current subscription expire? What anti-spyware applications (other than Defender) are installed? What third-party firewall (if any)?
3. Has a(nother) Norton application or a McAfee application EVER been installed on the computer since you bought it?
4. 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.)
5. Are ALL of the following updates listed in View installed updates (not Update History)? [1]

    (a) KB2846071 & KB2850851;

    (b) KB2845690, KB2839894 & KB2830290;

    (c) KB2813170, KB2813347, KB2840149 & KB2807986;

    (d) KB2790113; KB2676562 & KB2644615.

6. Assuming Java is installed => Is Java Version 7 Update 25 (or higher) installed? TEST HERE USING INTERNET EXPLORER ONLY! => http://java.com/en/download/installed.jsp
7. Is Adobe Flash Player v11.8.800.94 installed? TEST HERE USING INTERNET EXPLORER ONLY! => http://www.adobe.com/software/flash/about/

8a. Is IE9 or IE10 installed?

8b. Is Firefox, Chrome or any other alternate browser installed?

9. Are you in the habit of using "Registry cleaners" (e.g., Registry Mechanic; System Mechanic; RegCure; RegClean Pro; Advanced SystemCare; Registry Booster; McAfee QuickClean; AVG PC TuneUp; Norton Registry Cleaner; PCTools Optimiser; SpeedUpMyPC; PC Doctor; TuneUp Utilities; WinMaximizer; WinSweeper; Comodo System Cleaner; Advanced System Optimizer; CCleaner Registry Cleaner)?

==============================================

[1] Start | Control Panel | Programs and Features | View installed updates (in left-hand menu)

Answer 5

.NET Framework Cleanup Tool:

http://blogs.msdn.com/b/astebner/archive/2008/08/28/8904493.aspx

OT @TauArian: Since .NET 3.5.1 is included in Win7 by default , [1] would running the .NET Framework Cleanup Tool be worthwhile here?

=====================================================[1] http://blogs.msdn.com/b/astebner/archive/2007/03/14/mailbag-what-version-of-the-net-framework-is-included-in-what-version-of-the-os.aspx