Windows Vista “Could not open input file”

I get this strange error when I try to run a php file from anywhere in the system:

Could not open input file: drush.php.

...except for its own directory. When I try invoke it from its own directory, no problem -- everything works!

Is there a permissions issue here? I looked under security tab in the properties for the file, but every user was given all the permissions that are available.

So I don't get why Windows is not able to open this file from any other directory except where it is located.

From serverfault picardo

• It could be a "working directory" issue. Have you tried making a shortcut to it on the desktop, then right-click, properties, and change "start in" to the folder where the php file is?

  picardo : yeah, that worked. so what do you think i should do? keep using the shortcut rather than the batch file? -- i dont know if i mentioned that the file is being invoked by drush.bat.

  Adam Brand : You could use the shortcut or edit the batch file to do "cd c:\yourpath" before it runs that command. You might also want to try t the PATH comment below to see if that does the trick.
  From Adam Brand

• Try adding the path of the PHP bin folder to your %PATH% environmental variable

  Usually in C:\Program Files\PHP\bin (or C:\Program Files (x86)\PHP\bin) or C:\PHP\bin

  picardo : actually i tried that. it didn't work. same error.
  From Jack B Nimble