virtualbox.org

and in the safe mode - the same problem. Driver doesn't set.

You have somehow messed up your system. I don't know how. But, I told you to first uninstall the GAs and reboot the guest. Did you do that, or did you try to straight install the new ones over the old ones?

Yes, I did, as you said to me. Even more, I rebooted host system too, but result the same - driver doesn't install.
I can't install GA now, so I reinstall it in host system and repeat GA install in the guest.

As far as I can remember you're the first person that has ever had a problem installing the GAs. I couldn't begin to think what is wrong with the guest...

I reinstall host system on Linux Fedora 25, and try to set GA in Windows 7 again. But the problem remains. I can't install GA.
I made new virtual machine. But no luck.
What should I do next?

Which edition of Windows 7 are you trying to install?

Win 7 SP1 x86 Version: 6.1.7601.18489

Just a moment, I'll write you later. I remembered I explored %windir%\system32 - maybe I harm access rights in this directory. So, I will reinstall Guest OS, and check again.

I have done it. The problem was in guest OS. Now it's all OK.
cheers.

Great!
Could you share the solution, so that others can benefit in the future? You simply reinstalled the guest OS?

Yes, I have just done it.

OK, thanks, I'll mark the thread as [Solved].