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

.NET Framework Setup Verification Tool User's Guide

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

Verification completed successfully for each version of .NET from 2.0 to 4.0. Do i need to publish logs?

.NET Framework Cleanup Tool:

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

I've already tried this tool, it didn't help to me. It cannot do anything with .NET 3.5.1 because (as far i know) it's a component of system in Windows 7.

Answer 2

Please answer each of the following [admittedly tedious] diagnostic questions

This isn't tedious, i'm glad to see someone trying to help me.

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

I didn't purchase whole PC, i've bought each part separately in April 2013.

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?

I bought it and did a clean install.

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

Sorry, i didn't understood correctly what you meant to say.

2. What is the full name of your installed anti-virus application or security suite and when (approx. date) does your current subscription expire?

Dr.Web Security Space 8.0, subscription expires in Sep 2013. This solution includes anti-virus and firewall.

3. Has a(nother) Norton application or a McAfee application EVER been installed on the computer since you bought it?

No.

4. Did a Norton free-trial or a McAfee free-trial [pick one] come preinstalled on the computer

No it didn't because there was no any OS in my PC when i bought it.

5. Are ALL of the following updates listed in View installed updates (not Update History)? [1]

Yes.

Is Java Version 7 Update 25 (or higher) installed?

No.

8a. IE10

8b. Yes, i have Firefox and Waterfox installed.

9. No, i don't use such tools.

Answer 3

1. Assuming Java is installed, what Java version is currently installed (i.e., since it's not Java 7 Version 25)?
2. Repost: Is Adobe Flash Player v11.8.800.94 installed? TEST HERE USING INTERNET EXPLORER ONLY! => http://www.adobe.com/software/flash/about/
3. Is IE10 or Firefox your default Browser?  [Note: Your preferred browser may not be the system's default Browser.]
4. Is the inability to enable (turn on) or disable (turn off) .NET Framework 3.5.1 a sudden, new problem?  In other words, could you ever enable and/or disable .NET Framework 3.5.1?
5. After you installed Win7 in April 2013, how long was the computer connected to the internet before you got Dr. Web Security Space (any version) or any other anti-virus application installed?
6. After you installed Win7 in April 2013, which did you do first: (a) Checked for & installed updates; or (b) got Dr. Web Security Space or another anti-virus application installed?

Answer 4

1. I don't have any versions of Java installed on my PC.
2. Yes, it is. I've tested it with IE 10.
3. No, it isn't.
4. I didn't tried to enable/disable .NET 3.5.1 before on this PC, BUT i disabled and then enabled it without any problems in clean Windows 7 on virtual machine.
5. Do you think this problem caused by malware? Well, i've installed this AV immediately after OS in same day, and i didn't surf any "dangerous" sites. And i did full scan of my system several times, Dr.Web didn't find anything.
6. At first i checked & installed upd, then got Dr.Web.

Answer 5

Q: After you installed Win7 in April 2013, which did you do first: (a) Checked for & installed updates; or (b) got Dr. Web Security Space or another anti-virus application installed?

A: i [first] checked [for] & installed [updates], then got Dr.Web [installed].

Ideally, you would have installed Dr. Web (or another anti-virus application) within seconds of first connecting the new computer to the internet.

Since you didn't, you may be seeing the effects of an ongoing infection of some kind.

Note: If the computer was already infected, Dr. Web would not have installed properly & therefore wouldn't be working properly either.

Again, an infection is only one possible cause of the behavior you're seeing so it's worth checking it out.

OPTION A: For assistance with identifying/removing a possible infection, begin your own, new thread in this forum => http://answers.microsoft.com/en-us/protect/forum/protect_scanning or this one => http://answers.microsoft.com/en-us/windows/forum/windows_7-security

OPTION B: You may obtain Microsoft-sponsored Premium (i.e., paid) Support via the Answer Desk => http://answerdesk.microsoftstore.com [1]

OPTION C (Recommended, since Win7 hasn't been installed for very long): See...

   • Cleaning a Compromised System

      http://technet.microsoft.com/en-us/library/cc700813.aspx

Then see the (my) ANSWER post in this thread and follow those instructions (to-the-letter &in order! ) to return your computer to a secure & functional state: http://answers.microsoft.com/thread/bc95f2f0-7968-4bd0-8de5-70b83db31fa6

If you need additional assistance with the clean install of Win7, you can begin your own, new thread in this forum: http://answers.microsoft.com/en-us/windows/forum/windows\_7-system

If these procedures are outside of your technical "comfort zone" - and there is no shame in admitting this isn't your cup of tea - take the computer to a local, reputable and independent (i.e., not a "BigBoxStore" or the Geek Squad!) computer repair shop & let them do the work.

**Note: The computer should NOT be connected to the internet *or any local networks* (i.e., other computers) in its current state. All of your personal data (e.g., online banking & credit-card passwords) should be considered at-risk, if not already compromised.**

Wish I'd had better news for you. Good luck!

*I have nothing further to contribute to this discussion so I'm no longer monitoring this thread.*

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[1] $99.00 USD for "up to 2 hours" of remote support; fee must be paid up front; *no guarantees whatsoever!*