This is yet another guide to help you backup your Battlefield 3 before you format your Pc and reinstall. I followed the guide here: http://forums.electronicarts.co.uk/b...l#post20550288
Below is a edited version to what I did that worked for me.
1. Go to where you installed Battlefield 3. I installed it here: C:\Program Files (x86)\Origin Games
2. Make a copy of the Battlefield 3 folder and put it somewhere safe (different hard drive/external). Also save the Battlefield 3 folder in your Documents if you want to save your settings ect. I personally did this.
3. Download, install and login to Origin. Origin will start to try and download Battlefield 3, right click it and say Cancel Download. Then go to the settings cog at the top then click settings again. Under General change the Downloaded Games location to where you want Battlefield 3. Close Origin and make sure it's not running in the taskbar.
4. Copy the backed up Battlefield 3 Folder to where you want Battlefield 3 to be installed. If you copied the Battlefield 3 folder that was in your documents then put it back also.
5. Open notepad and paste this:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\EA GAMES\Battlefield 3]
"GDFBinary"="C:\\Program Files (x86)\\Origin\\Origin Games\\Battlefield 3\\GDFBinary_en_US.dll"
"Install Dir"="C:\\Program Files (x86)\\Origin\\Origin Games\\Battlefield 3\\"
Change the GDFBinary and Install Dir lines to where you want to install Battlefield 3, remember to have \\ instead of \
6. Save the notepad doc as bf3.reg, to do this select "All Files" under the drop menu "Save as type".
7. Run the file and add it to registry.
8. Open Origin again and leave it for awhile, it will be saying Preparing on Battlefield 3 for about 2mins.
9. When It stops saying "Preparing" right click Battlefield 3 in Origin and then click "Repair Install" it should then download about 100mb, once it stops you are all good to go. - DCWarhound
10. If you're getting PB issues online, go to where u put the Battlefield 3 folder and run pbsvc. This should reinstall PB
11. (Optional) Manually update PB.
I do not guarantee this guide will work for you, but as long as you backup your Battlefield 3 you can always try a different guide. This guide worked for me on my Windows 7 64bit.