What Anny is saying is.....
After you've installed the game, perform the following steps:
(btw...be careful when in the system registry, do not ever delete/change anything in your registry if you're "not exactly adept with PC's"
)
1. Navigate to the system registry editor (START >> RUN >> REGEDIT >> ENTER)
2. Check the "tree" on the left and expand it (along the proper "branches") until you get to:
HKEY_LOCAL_MACHINE\SOFTWARE\Stardock\Dregnin.net\sins
and as Annatar has pointed out, you should see various data in the fields.
3. Re-boot your machine, then check the registry entries again.
That's Annatar's advice step-by-step for the "not exactly adept with PC's".... 
By the way.....
Is the account on this PC which you're installing SINS through a "limited" user account by chance? If so, please re-isntall SINS using the administrator account, or by right-clicking on the installer and selecting "runas".
thanks,
the Monk