External hard drives, no matter how fast they are, (IDE or SATA) can only be accessed at USB speeds.
That is excruciatingly slow, compared to an internal HD.
That's why they are not used to run programs as HD intensive as a SIMS game would be.
External HD's are best used for backups and storage.
Install the game back to your main HD and it will work OK.
Then delete all the junk off of your internal HD and you'll have plenty of room for the game.
Start with two MS programs already on your computer, "Disk Cleanup" and "Defrag" to improve HD performance.
Cheers Mate!
The Doctor
