Iphone 4 backup question

[Stpilots98]

I recently upgraded 5.1 from 5.01 on my iphone 4 and saw a considerable drop off in my battery. 5.01 however did worlds for my battery.

My questions is if I have a backup on my computer of my phone when I was running 5.01 will the backup restore my phone to that IOS? Thank you in advance

 

[Small White Car]

Nope. Backups are your personal data only, not the OS itself. There are ways to downgrade (sometimes), but Google will have to help you with that. The backup won't do it.