The Sims2 Error!

Ok we have had the sims before and they have always worked fine until sims2 pets and then we had a problem.  We kept getting an error message about "please insert the correct dvd-rom, select OK and restart application" well this drove my dad mad for about 3weeks and in the end he either removed the sims or moved them i don't know what he did but the sims are no longer on the computer.  Now that I have the computer I am trying to install the sims2 again but i get the same error message coming up saying "please insert the correct dvd-rom, select OK and restart application".  I know the computer takes DVD-ROM games as I was able to use World Of Warcraft the burning crusade which is DVD-ROM.

The first time we had the sims on it was the sims2 PC CD-ROM and it worked.  I'm trying to reinstall it but now the CD-ROM version wont work.  I thought I would bypass this and load on the sims2 open for business to see what would happen but now i get this error message "Please ensure The Sims 2 Open for Business disc is in the drive, select ok and restart the application." but the disc is in the drive and i've tried both drives and still get the same message.

Can you please help me?  Dont know if this is any good
1. Model number of your computer - if i use system properties and look at computer i get, AMD Athlon(tm)XP 3200+

2. What Operating System - Microsoft Windows XP 

3. How much main memory installed - Physical Memory, 1024MB (2x 512 DDR-SDRAM) Hard Disk, Samsung(160GB) 2.19 GHz, 1.00 GB of RAM

4. What Video card - ATI Technologies INC Radeon 9250 (RV280)

5. Drives -

Drive D: (DVD-Rom)

Model, AOPEN DVD1648/AAP

Peripheral Type, ATAPI

Disk Type, CD-Rom Data

Drive F: (DVD-Rom) this is the one I use for all games

Model, LITE-ON DVDRW LH-18A1P

Peripheral Type, ATAPI

Disk Type, CD-Rom Data