Is it safe/practical to manually update shell32.dll in Windows XP?

Question

I am running my development environment Windows XP. I need access to the function SHGetKnownFolderPath. My team proposes that I simply update my shell32.dll with theirs and update my header files.

The function is documented here: http://msdn.microsoft.com/en-us/library/bb762188%28v=vs.85%29.aspx

Now, understand that the focus of this question is on the viability of overriding/updating the shell32.dll manually via copy-paste. Please do not respond with workarounds/alternatives to the function mentioned above. That is not the point of this question.

Is it safe to simply take the Windows 7 version of shell32.dll and paste over mine (in XP)? I am afraid to test that for fear of murdering my entire operating system. I do not know all of Windows' library inter-dependencies and whether this would even be compatible. It sounds incredibly unstable, but that is what is being proposed I do.

Answer 1

You should not change a Windows DLL manually. A Windows 7 DLL will have dependencies that will not resolve on XP. Even if this worked (very unlikely), next time you install a patch from Windows Update it may either break due to dependencies or replace your Windows 7 DLL back to XP version.

UPDATE: This just won't work. The Windows 7 DLL has dependencies on API sets which did not exist in XP.

Answer 2

1. Copying manually the dll via copy-paste will not work, because WFP will kick in and restore the original dll. IIRC only digitally-signed updates from Microsoft are allowed to replace system dlls on a running system to avoid messes like this. You should replace the file offline (eg from another copy of Windows/BartPE/Linux/...), or disable/workaround WFP in some way. So, it's not practical.

2. Taking a system dll from another version of Windows and copying it there seems like a terrible idea. The shell changed a lot from Windows XP to Windows 7, I'm sure that there will be a lot of missing dependencies. Even if you managed to copy every file of the Windows 7 shell to Windows XP, these files would depend from newer user32/gdi32/ntdll/... functions added in Vista and 7, so it would not work anyway.

3. So, I think that the most probable consequence of replacing shell32.dll would be the failure to load almost any non-core component of the OS: failing shell32.dll to load due to missing dependencies, almost any GUI executable that links against it would fail to start. So, it's not safe.

4. Other than being a problem from a technical standpoint, I strongly suspect that it's also illegal. Having a license for both Windows XP and Windows 7 would not help, I think that this is considered "modification of the software product", that is explicitly disallowed by the Microsoft EULAs. So, it's not legal.

5. If you want backwards compatibility with XP just use SHGetFolderPath instead of doing all this mess.

Answer 3

Is it safe/practical to manually update shell32.dll in Windows XP?

No.

Answer 4

shell32.dll is a core operating system file. I would expect that minus the other dependencies underneath the Windows 7 version you would have all sorts of unexpected behaviors. It would be better to test within a VM a complete Windows 7 environment rather than copy over a part of another version of an operating system.

Bigger questions: Do you think anyone at Microsoft every tested this exact combination? If you run into issues and you call support do you believe that you will find that your configuration is a supported one for your efforts? Having worked for MSFT in the past I would think that the answer to both is likely not.

Answer 5

Probably they know what they're saying. Anyway I would suggest you creating a system restore point and, just in case, downloading a minimal linux distribution so that, in extreme cases (ie windows can't boot), you simply restore their shell32.dll with yours.

Answer 6

I don't think so... But if still want to try, then i suggest you install a virtual machine and try it there. this way much safer.