Backyard Designs

I have almost all the sim 2 games, expansions, and stuff packs. I have The Sims 2 Deluxe, The Sims 2 Bon Voyage, The Sims 2 Seasons, The Sims 2 Free Time, The Sims 2 Apartment Life, The Sims 2 Pets, The Sims 2 University, The Sims 2 Open for Business, The Sims 2 Teen Style Stuff, The Sims 2 H&M Fashion Stuff, The Sims 2 IKEA Home Stuff, The Sims 2 Glamour Life Stuff, The Sims 2 Kitchen & Bath Interior Design Stuff, AND The Sims 2 Mansion & Garden Stuff. I have all them loaded into my computer. And when I go to play The Sims 2 Mansion & Garden Stuff (cuz thats what it tells me to play) When I try to put in a code I hold down all together (ctrl, shift, c) and the cheat window will never show up. Do I have to press something different or will this game just not accept cheats? Please will someone help me??
I just got this computer last night so its new to me and Chuck…. how do I switch to XP mode?
How do I switch from vista to XP? Some please let me know…PLEASE???!!!
I have Windows Vista(TM) Basic. Will that change anything? I just want to be able to play my Sims games and put in cheats so please someone please answer this stuff for me pretty please…

Step into the gardening business in this intriguing simulation game, where you build and decorate your own garden of flowers, animals and vegetables. Follow the market trends, get to know your customers and serve ripe crops down at the town market to expand and get your business profitable. Harvest many different crops and enrich your land with animals as you earn more than 10 special awards. Design your garden the way YOU like it with Alice Greenfingers!

I have the sims 2 for pc and the following games/add on’s:
The Sims 2
Bon Voyage
University
Open For Business
Pets
Night Life
Free Time
Glamour Life Stuff
Celebration Stuff
Family Fun Stuff
H&M Fashion Stuff
Mansion & Garden Stuff
Bath Interior Design Stuff
Teen Style Stuff
I want to sell them on ebay, they have been used by me but are in perfect working order. How much should I put them on for Buy It Now, I workind out that the RRP would be around £180