Anyone who wants to have their old Sidebar back this is how you do it.
First you need to go to your programs folder, not programs (x86), then go to the sidebar folder and take ownership of all the files and give yourself full control.
Once you have done that you can make a copy of the sidebar folder and rename it as sidebar-backup and then delete all your files that you can in the sidebar folder.
Now go to your Vista programs folder and copy the files from that sidebar folder and paste them in your Windows 7 Sidebar folder.
Log off then on again Right click on the screen and select Gadgets and you can put them on again.
Also if you want all your old Gadgets you had installed on Vista, go into the Appdata/Local/Microsoft/Widows Sidebar and copy those files into the same place on Windows 7 and you will then have all your old Gadgets back.
Hope this Helps you all, I know it made me happy to have it
. Full Tutorial Can be found here Vista Windows Sidebar - Reinstate on Windows 7