I have a question very similar to this one but the answer does not work for me.
Software I am maintaining the setup for depends on VC++ 2008 (SP1, precisely), thus I need to find a solution to install VCRedist if not yet installed. I understand the correct way would be to build msi with merge modules, but it's not on my hands.
The answer of the duplicate question I am referring to (the accepted one) does not work for me because every tiny release (e.g. 9.0.30729.01 vs 9.0.30729.17) has proper GUIDs, which I am not able to guess or predict for future versions. Furthermore, I reckon that this would not detect Visual Studios and thus unnecessarily install the VCRedist Package when it's already on a developers machine. I do not want to bug anybody with this, certainly not somebody who has already a DevStudio installed.
Now another answer says I should look in the WinSxs-folder like $WINDIR\WinSxS\x86_Microsoft.VC80.CRT_ but this does not (yet) help me to imply SP1, or is there anything I am missing at this point ? Is there a table somewhere with the internal and "external" version numbers, so I could imply a certain minor version number ?
I cannot believe that there is nothing provided by Microsoft for this scenario, but searching the interwebs for already far too long now brings me back to good ol' SO :)
You could take the recommended approach for installing directx: always run the redistributable. Since it's required and you're already shipping it there's no harm in running it even if it's already installed.