PSP X4 install file or PSIService reg key

[dosdan]

I'm getting an "illegal or modified program" msg when I go to start PXP4. I must have deleted the registry entries for the PSIService when I recently ran a registry cleaning program.

I used to keep the original PSPX4 install program (I purchased online) and I've reinstalled in the past that way. However recently I deleted this file as I no longer thought that I'd need it and it was taking up space.

There does not appear to be a link to the original PSPX4 install file on the current website. Can ANYONE provide a link so that I can download the PSPX4 installation program?

Or alternatively, the registry entry that I need to recreate to run PSIService at startup?

Dan.