Sims 2 installation help. please...urgent. desperado here...?

Ok, i've installed the sims 2 super pack 2007 (the sims 2 original, university, nightlife, open 4 business, holiday and family fun stuff) into my laptop and it works perfectly fine. but when i try to install the sims 2 seasons from a separate cd, a dialog box occurs saying, "the sims 2 is not installed or improperly installed in your machine. Please install or reinstall the sims 2."

isn't it that the original sims 2 is included in the pack?

i've tried installing patches from the sims 2 website, but i still get the same dialog box i came across during the seasons installation.

is there anyway i could install other sims 2 expansion packs which were not included in the super pack like seasons, pets or glamour life etc....?

i've read in other forums that you can in fact install other EPs and SPs but some doesn't really help that much while others are explained so vaguely.

please help and explain in details. i will surely award 10 points to the best SERIOUS answerer.

THANKS IN ADVANC