How to repair or re-install .NET Framework 2.0

My OS is Windows Vista Ultimate. When I tried to install some programs which require .NET Framework 2.0, the program cannot neither finish the installation nor run. The software providers tested the software carefully with Windows Vista and some users can use the software without any error. The problem remains the corruption or any bug in .NET Framework 2.0. How can I restore it to original version, or reinstall .NET Framework 2.0 ? Is there any bug fix which I need to update ?
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Remove the framework using Control Panel > Add / Remove Programs

Download and install from:
free4vnAuthor Commented:
Thank you for your comment, but:

1. If you use Windows Vista, you will know that .NET Framework does not appear in Programs and Features (aka Add / Remove Programs in Windows XP and previous versions).

2. Please give me the exact URL instead of a URL relates to all issues of Microsoft .NET Framework.
The .net 2.0 framework is a component of the Vista OS, and as such cannot be uninstalled/reinstalled by itself.  In order to repair it, you would check for corruption of the Vista install itself.  sfc /scannow will scan your system and offer the option to repair any problems found.  The below links offer some more information:
free4vnAuthor Commented:
Thank you for your comment, michko.

I tried sfc /scannow as said in

It took 5 minutes and then it said that there are some problems which it cannot fix, and generate a log file whose size is about 6MB. I don't have much patient to read all that text file. If you can understand that log file, I will send it to you.

The content of webpage is similar your comment here, and also mention about the above link.

As far, I just see one solution, that is repair the Windows. I don't want to do this. Is there any other solution?
Nope.  Being an integrated part of the Vista OS, you'll have to repair Vista to repair .net.  

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Windows Vista

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