sv4 files

On the SFNE recreation and InSomniA park that I've downloaded, I haven't been able to open them because my computer can't open the .sv4 file.  Is there a patch or something that I can do to see these parks?
-----------------
B&M of New Jersey=best baked beans
B&M of Switzerland=best rollercoasters

I have xp prof if that helps.  Anyone???
-----------------
B&M of New Jersey=best baked beans
B&M of Switzerland=best rollercoasters

Do you have the Drexler patch?
-----------------
I tried to sign my name here but the ink didn't stay on the screen.

You need the Drexler patch, but you also need to open it while in RCT.