iPhone OS 4.0 upgrade. Lost my data and got it back

I recently tried to upgrade my iPhone 3Gs to iPhone OS4.0 using windows

Here's what happened

1. iTunes updated itself.
2. iTunes Backed up iPhone
3. iTunes attempted to upgrade phone.
4. iTunes hung half way through install
5. I rebooted and restarted iTunes and the install completed.
6. iTunes attempted to restore the old backup.
Result: all my data was gone. (texts, emails, notes, photos)... very disappointed.

Next:
I repeated the process.... and tried to reinstall an old backup....

Result:
No luck, turns out the new iTunes update deleted all my old backups ... not happy

How i fixed my phone:
Luckily I use Windows 7 and used the Previous Versions functionality to retrieve old backups.

1. I located the backup folder (usually C:\Documents and Settings\USERNAME\Application Data\Apple Computer\MobileSync\Backup)
2. Right click the backup folder, goto properties>Previous Versions
3. Hopefully you'll see a old version of the backup from a time before you started the process (it should be a large file, mine was 185MB).
4. Copy this file into the Backup folder.
5. Open iTunes and attempt to Restore the backup.

Result:
My phone was updated to OS4 and all my contacts,photos,texts and notes were restored :)