AviSynth install problem: Could not copy avisynth.dll to system directory

[mike23]

When I tried to install the latest avisynth software a message windows pops up informing me that:

"Could not copy avisynth.dll to system directory - close down all applications that use avisynth, and sure to have write permission to the system directory, and try again"

This was rather surprising because I did currently NOT use avisynth or any other video program. I found out that a previous installation wrote its dlls into the system directory. And these dlls were locked during boot time. Unfortunately the previous avisynth installation was NOT listed in the software uninstall control panel (Add /remove programs). So the only (last) help was to click on the uninstall.exe in the installation directory.

This requirement and procedure is rather unconvenient and misleading. Please could you introduce a new info message box: "Uninstall previous avisynth first" or - even better -
uninstall previous avisynth installation automatically during installation of new avisynth. Or just let it unlock and overwrite the old DLLs.

Thank you

[Wilbert]

This requirement and procedure is rather unconvenient and misleading. Please could you introduce a new info message box: "Uninstall previous avisynth first"
We will add something like this for the next version.

[IanB]

Hey WHAT :confused: the installer is designed to install over existing versions already.

The question here is why was your avisynth.dll locked if you were not running anything.

There are many many protectionist programs available now that try to hinder viruses and malware from installing themselves. These also hinder valid installs in the same manner.

We will see if we can improve the text of the messages and some of the logic to make things easier.

[winny]

Ive just had the same problem myself and though Id share my solution.

Looking for avi*.dll in c:\windows\system32 showed there was no file called avisynth.dll present. However the file was there but had attributes to make it hidden and read only.

Typing "attrib -r -h avisynth.dll" removed the attributes and allowed me to overwrite it with a fresh install.

Hope this helps others.

[unskinnyboy]

I have armed myself with this freeware handy tool called Unlocker (http://ccollomb.free.fr/unlocker/) for situations like this. After installation, this tool will be added to the context menu, so just right-click on avisynth.dll, choose Unlocker and it will show you all the processes using the DLL. For all you know, some stray process might have been using it! You could then unlock it or kill the process(es) itself.