FileExists() returns false, even if file exists
I want to check if a dll in System32 directory (Windows 7) exists. But even if it exists, FileExists() returns false. LoadLibrary returns a valid handle. In this case, I only want to check, if the files exists and visualize this information. Do you have a any tips to solve this?
Answer
Most likely this is down to file redirection. You have a 64 bit machine but from the 32 Delphi process, Windows\system32 actually redirects to Windows\Syswow64. So when you think you are asking for the existence of a file in Windows\system32, the system is actually reporting the existance (or otherwise) of a file in Windows\Syswow64.
If you really do need to see into the true 64 bit system32 then you need to disable file redirection. You can do this with the Wow64DisableWow64FsRedirection() function. Don't forget to switch it back on with Wow64RevertWow64FsRedirection(). Beware that disabling the redirector has wide reaching effects and can result in very strange behaviour so do so with care.