In version 3.51.01, I have once again revised how Sandboxie handles the WINSXS mechanism in Windows.
Earlier versions of Sandboxie tries to emulate WINSXS by making copies of folders from the sandboxed C:\WINDOWS\WINSXS folder into the sandboxed application folder. The end result was a lot of duplication of folders with names like MICROSOFT.VC90.CRT, and a mess of .MANIFEST files everywhere. And more importantly, it only worked some of the time, as some complicated installations would also confuse the Sandboxie WINSXS emulation.
I've explained this problem before in a post here:
In version 3.51.01 all of this should work much better as Sandboxie can now run the "real" WINSXS mechanism in the sandbox, instead of trying to emulate it. This means no more duplicated folders, no more .MANIFEST files everywhere, and most importantly -- hopefully more successful installations of software into the sandbox.
This is a major change even though it is behind the scenes, and while I did try to test it extensively, there would likely be a few problems here or there. So please let me know if you find something strange.