error opening file for reading

Hi, i have a persistent problem with my installer. When the installer tries to copy the installation files into the installation directory, for each of the files the message "error opening file for reading: %filename%" pops up. The dialog gives me 3 options: retry, abort and ignore. I have tried anything from changing permissions on the files and folders to hacking the registry. I need help!

The files are in use by another application.

"The files are in use by another application."

i dont see how that could be the case, but it certainly looks that way...

Try to write to the files manually. It that doesn't work they are in use.

Writing to the files manually works. When i try to run the installer (Setup.exe) on another windows box, it still fails with the same message. It is a complete mystery to me what causes this right now.

Maybe the filename is invalid.

nope, this installer worked just fine on my laptop running windows xp home (which i left at home today). the only thing i have done now is to copy the new executable + some dll's into the directory and rerun the install script to generate setup.exe. I suspect it has something to do with windows xp professional.

Please attach your script.