Hi There,
here is tricky (for me) issue:
1. Windows 7, SP1.
2. I have lots of C++ redistributales in C:\Wimdows\winsxs like
'x86_microsoft.vc80..' and 'x86_microsoft.vc90..'.
So I do have them installed but when I check if I have them 'legally' installed using all possible uninstallers including native one I do not see them installed!?
So I even cannot uninstall them.
3. When I try to install driver for the HP printer I've got:
"An error occurred during the installation of assembly 'Microsoft.VC90.CRT,version="9.0.30729.1",publicKeyToken="1fc8b3b9a1e18e3b",processorArchitecture="x86",type="win32"'.
Looks like it tried to install a new one but..
So is there any way to cleanup all this 'redistributable' mess?

3. When I try to install driver for the HP printer I've got:

Have you tried posting at HP Support Forum?

Trying to get rid of the various C/C++ runtime versions you have installed, is not a good idea, since likely quite a lot of software you've got installed depend on them.

1. I think, I have this issue with 'hidden' redistributables.
I mean, I do not see them in Add/Remove!? None of the uninstallers sees them,
but they present as files and have some related entries in registry.
That is why I called them 'hidden'.
2. I did not post it on HP because when I tried to update (or install) them from vcredist_x86.exe I've got similar error.
More to it, when I run Win 7 update it failed on .NET 3.5.1.
So I guessed that there is something wrong with these redistributables.
3. HP installation error says "installation of assembly".
I think, this means that it tried to install it (Microsoft.VC90.CRT,version="9.0.30729.1") but could not. And why did it try to do it, - files were already there?!

P.S. I posted the issue on HP forum, and the answer was that
I have to repair Windows Install and/or .NET files.