Where can I download Final Cut Express 4.01

Bought Final Cut Express 4 years ago and have it on my Macbook Pro but reloaded on my more recent imac. The macbook software was upgraded to 4.01 and all the projects I created on it cannot be read by 4. Can anyone tell me where I can find the version 4.01 upgrade to download? I know this has come up before and I have followed a few leads but to no avail.