How to Install Older iOS Simulators in XCode 4.2.1 (SDK5.0)

X-Code 4.2 will have iOS 5 simulator and library only. If you want lower version simulator and library with X-Code just goto X-Code->Prefrences-> Downloads Tab. In downloads tab you'll have two tabs:

1) Components - Here you will have option to download iOS 4.3 simulator(~600 Mb), iOS 4.0-4.1(~670 MB) Device debugging support, iOS 3.0-3.2.2(686.3 MB) Device debugging support.

2) Documentation- Yoy will have option to download iOS 5.0,XCode 4.2 Developer libaray,Mac OSX 10.7 Core Library.

Install the components which ever you need and there you go..Have you installed components this way??

If Xcode doesn't show the wanted simulators you'll be able to download older xcodes from here:https://developer.apple.com/downloads/index.action?name=Xcode

For example:

• iOS 5 Simulator -> Xcode 4.3
• iOS 5.1 Simulator -> Xcode 4.3.3
• iOS 6 Simulator -> Xcode 4.6
• iOS 6.1 Simulator -> Xcode 4.6.3
• iOS 7 Simulator -> Xcode 5
• iOS 7.1 Simulator -> Xcode 5.1

You can find the Xcode application inside the downloaded .dmg

1. Open this DMG
2. Right click on the Xcode application and click 'Show Package Contents'
3. Navigate to: Contents/Developer/Platforms/iPhoneSimulator.platform/Developer
4. Copy the found simulator folder (eg. iPhoneSimulator7.1.sdk folder)
5. Repeat steps 2 & 3 for your current Xcode application
6. Paste the simulator folder

Restarting Xcode will show you the new added simulators

Happy building & testing!

Update:
Tested in xCode 6, working there as well