SPWIZENG.DLL is not a valid windows image

I need help to install Windows Vista Beta edition. I have a system which has XP and I had verified that Vista is going to work on the same. When I started the installation after a few minutes I got a error saying that spwizeng.dll is not a valid file. The setup simply crashed on that. I am not able to figure out why this error appeared. I cannot find the exact cause behind it. I tried the setup again from scratch and the same error appeared. I had downloaded Vista from web. And the download was fine. How to fix this issue. Thanks.

I am trying to run the setup by mounting the iso image through daemon tools. I could not understand why Vista is not able to find that dll files. It looks the image file is not properly. I cannot put that back on download. I had already wasted a ample of bandwidth on it. I will see whether this works or not. The last option that remains is to re-download the same back again one more time.

It is a great disappointment. After downloading around 3GB of data I am too stucked with the same error. I tried to find that file on web, but there is very less information available on that. I had downloaded the iso file in night and burned that on a DVD using Nero. It just like a waste of entire time I spend to get the download.

I am getting that error on Windows Vista Business Edition. I thought the issue lies with the DVD. So I burned a different one. There are now 3 copies of Vista with me an none of them are working. So this is clear that the iso file which is provided on the web is buggy and has this kind of problem.