Is Windows registry redirection a “bad thing”?

Question

I have my own installer program which I use to install several applications I have written.

I have been updating this program to avoid the application's data file updates going to the user's VirtualStore, as I read this was a "bad thing". I am doing this by storing the program and common data files separately in their correct locations, instead of sticking everything in Program Files like we used to do in the days of XP.

I am also now using SHGetFolderPath (yes, it's deprecated, but I still need to support my XP users), to get known folders instead of trawling the registry, which is another "bad thing" (I read).

The next thing I was trying to do was rewrite the installer code to avoid registry redirection to Wow6432Node when writing stuff to HKLM, as I thought this was another "bad thing".

However, although I could put the application specific stuff that goes there (like the install folder, if the user decides to install in other than the default), the killer is the need to put the uninstall info in HKLM\Software\Microsoft\Windows\CurrentVersion\Uninstall. For 32-bit stuff running on a 64-bit system, this is redirected to Wow6432Node. I don't see any way round this - is it in fact possible?

Answer 1

UAC registry redirection could reasonably be described as a "bad thing" because it is designed specifically to provide compatibility with improperly written software, i.e., software that assumes it is going to be run with administrator privilege.

WOW64 registry redirection is a different beast; it's designed to provide compatibility with properly written 32-bit software. If your software is 32-bit, and has no specific need to be 64-bit aware, there's nothing wrong with letting it run in the emulation environment as-is, including allowing registry settings to be redirected to Wow6432Node.

You can bypass WOW64 registry redirection if necessary, but you shouldn't do this arbitrarily, only if there is a specific reason. If WOW64 redirection worries you, the only good alternative is to provide a 64-bit version of your program.