Try this:

Go to Start/Control Panel, and double-click on Folder Options.
Now go to the 3rd tab - "File Types"....on my system (XP-Pro SP2 v5.1), near the top of the list, is an entry that looks like (NONE) - DVD, (listed under Extensions - File Types).
Highlight it, and see what you can change under the Advanced-button below.

Not sure if this will help you, as I never touched those settings myself.
I think that you once made a mistake after inserting a dvd: like checking "always perform this action" at the popup menu that you got back then, and you picked "Open in Windows Explorer"?

Anyway, maybe I'm pointing you into the right direction to find a fix.

isnt sh3 a dvd?

Yes

Paajtor i tryed the folder options thing like you told me to but i couldn't change anything in the advanced options thing. My computer sucks.

Ok...
Insert the SH3 dvd, and find the file called SH3Autorun.exe in Windows Explorer...double-click it.

It just shows the same error message as when trying to open setup.exe or any other file on the disc.

Nokia,

How did you uninstall SH3?

Add/remove application

For a complete uninstall, you also need to delete the SH3-folder in your MyDocuments, and then reboot.

I have deleted it but it still won't work!

When I get problems like this, I just reformat my hard drive or use "rollback". You will literally waste hours trying to find the thing when a rollback only takes a few minutes.

Can I add that an uninstall will still leave loads on your hard drive that you'll need to remove manually. Any mods ect are all left there so it might be worth checking (asuming you haven't already)

Good luck mate

Maybe it's possible to copy the content of the dvd to your harddrive, and install from there.

But I wonder, if StarForce likes that...allthough SF is only installed the 1st time you load the game, ie. when you have the dvd in the drive.
So I hope SF searches for the disc at the correct location.

I've had some success installing from another administrator-type account in XP (create a new account). This will bypass any user-specific problems your Windows might have. Doesn't always work, and won't fix the underlying problem if it does work, but it might allow you to get it installed.

Otherwise, most commonly this problem is caused by:
1) Wrong Windows version (like XP 64bit) - get a new Windows
2) Dirty disc - carefully clean the disc
3) Faulty disc - return and get a new disc (try in another computer first)
4) Dirty optical drive laser - get one of those laser cleaning kits
5) Bad optical drive firmware - try to find updated firmware for your drive
6) Antivirus interference - disable antivirus and try again
7) Virus / malware - scan and clean your system

DEFRAG the HDD. That will help tremendously. :)