I Know EXACTLY how to solve this :-D
It is most likely because it was uninstalled improperly. Below are steps to install the Sims 2 manually, which I got from EA's response to this problem, which I also had. But after I did each of these things correctly, everything's working fine. It installed correctly.
Here are the steps!!! :
For the CD edition:
Double-click My Computer.
Right-click on the Local Disk C and choose Open.
Right-click inside the window and select New, and then Folder.
Name the folder Disk Images it is important that the name has a space in it.
Double-Click the new Disk Images folder to open it.
Right-click inside the window and select New, and then Folder.
Name this folder Disk1.
Repeat steps 6 and 7 while substituting Disk1 for Disk2 and so on until there
are 4 'Disk' folders followed by a number 1 through 4. it is important to note
there must not be a space between "Disk" and the number.
Insert Disk 1 of The Sims 2 into your CD-Rom drive and if the autoplay starts,
cancel it.
Double-click My Computer to open it.
Right-click on your CD-ROM drive and choose Open.
When you see the contents of the disk in the Window, click on Edit at the top of
the window and choose Select All.
All the contents of the disk should now be highlighted, click on Edit at the top
of the window again and choose Copy.
Open the Disk1 folder you created under C:\Disk Images; click on Edit at the top
of the window and choose Paste. This will copy the contents of the CD into the
Disk1 folder.
Repeat steps 9 through 14 for the remaining disks until you have copied each
disk into its appropriate folder.
Once all the disks have been copied, remove ALL CDs from any drives.
Open the Disk1 folder under Disk Images and double-click on autorun.exe to start
the installation.
To save disk space, you can delete the Disk Images folders after the
installation has completed.
If you receive an error whilst copying the files this means the disk is either
damaged or defective. If the disk is clean with no visible scratches/damage,
you should exchange your copy for a new one through the store of purchase or our
Warranty Department. Please click here for the warranty information:
http://eatech.custhelp.com/cgi-bin/eatech.cfg/php/enduser/cci/warranty_information.php?p_sid=<?
echo $p_sid ? >
~~~
For the DVD version:
Insert the DVD into the DVD-rom drive. Exit the startup menu when it comes up.
Double click My Computer, then right click on the DVD-rom drive with the game
DVD in it and select Explore.
Hold the CTRL key and then hit A. That should select all the folders and files.
Then hold CTRL and hit C. This will not look like it does much, but it's
preparing to copy the files.
Close that folder and go to your desktop. Right click anywhere BUT on an icon,
and Select New, then Folder. Name the folder Sims2 DVD.
Then double-click that folder, and hit CTRL and V. This will begin copying the
files from the DVD.
Once the files are copied, remove the disc from the drive.
Double-click on the Setup icon in the folder.
You may delete the Sims2 DVD folder once the installation is complete.
~~~
It DOES work! Even though it's tedious, it's worth it because it works. Hope this helped!
If this DIDN'T help you, then let me know b/c then I can put other options that EA Tec help gave me.
:-D