Ah, I see.
I was able to fix my Construct launch error by downloading the vc 2005 redist SP1 from here. It is an older release than what you linked, as it required two security patches after, via Windows Update. Construct then worked fine and the MSXML4 was not reverted to a vulnerable version. I then uninstalled the patches and the vc runtime and reinstalled it from the link you gave--and MSXML4 wasn't reverted to an old version, either. I then reinstalled Construct itself and I've been unable to get MSXML4 to downgrade, either?!
So now I'm kind of clueless! D: I did not test for vulnerabilities exactly before and after installing Construct, so I can't say with certainty that something Construct installed has reverted the file's version. But on the other hand, I have not installed anything else in a long time, and I do run periodic vulnerability scans, so... yeahh.
One way to check would be to ask others what their versions are. The version you want to have is: Msxml4.dll, Msxml4r.dll (4.30.2100.0), found in C:\Windows\System32. Or just run a scan with Secunia PSI as described in the first post. :) You might find other vulnerable software while you're at it. :(
Oh and I doubt the vulnerability would be "outdated" if you have the vulnerable DLL sitting there. The page is old because the vulnerability is old itself.