Firmware please help

Hi I have just got my hands on a PSP Version 2.00 and I want to downgrade to the 1.5. I use this site and found a link that tells me how to do it and up to a point I was ok. It said that I should unpack MPHDowngrader file and Copy overflow.tif into the 'PHOTO' folder. I did this but I can not see the overflow.tif. All I have in MPHDowngrader file is Psp, Downgrader note,H and index.What is going wrong? Here is a link to the guild http://www.rjl.com.au/marketplace/Ar..._show.asp?a=21

Thanks
Gaz

The only idea that I have come up with is that my Norton is thing that it is a virus. And it is deleting it what ever I do it wont let me use it. And I really worried that maybe it is a virus and it will turn my psp into brick. But can I do I want to dowgraded it to 1.5.

Gaz

Try this. http://mphwebsite.tuxfamily.org/index.php?program=9

I use a different computer that does not have Norton on it to do the downgrading and it work like a charm. I now have PSP 1.5.

Thanks
Gaz