If you want to backup FF bookmarks, get from Mozilla's web site: MozillaBackup, version 1.51 -- that will backup a whole lot o' Firefox stuff. Now, why are you trying to reinstall Windows?
My Computer
At a glance
Windows 7 Professional 64-bitDesktop i5; Acers i5 & i7desktop 16GB; 1 Acer 8GB & 1 Acer 16GB
Computer type
PC/Desktop
Computer Manufacturer/Model Number
Antec desktop; Acer Aspire laptops
OS
Windows 7 Professional 64-bit
CPU
Desktop i5; Acers i5 & i7
Memory
desktop 16GB; 1 Acer 8GB & 1 Acer 16GB
Hard Drives
1TB split into 2 equal partitions [OS and data] usable by RJS
Internet Speed
AT&T DSL
Browser
FF, GChrome, msIE
Other Info
Windows 7 Firewall, Emsisoft AM/AV, MSE [scan-only], SpywareBlaster, Ruiware/BillP combine