Hi :wave:
The sims save game data is usually stored in C:\Documents and Settings\(username)\My Documents\Electronic Arts\The Sims 3. If you copy this elsewhere, then you can uninstall The Sims 3 from one drive and reinstall it properly on the other. Then paste the folder back where it was to use the save data.
EDIT: The installer should ask you if you want to keep files.
The sims save game data is usually stored in C:\Documents and Settings\(username)\My Documents\Electronic Arts\The Sims 3. If you copy this elsewhere, then you can uninstall The Sims 3 from one drive and reinstall it properly on the other. Then paste the folder back where it was to use the save data.
EDIT: The installer should ask you if you want to keep files.