Dear Silver DOllar Senior,
What are the addons your are tried to install?
Incompatible addons may cause the issue?
Boot your windows 7 DVD .On the installation screen select repair your computer option.Select the command prompt and execute the command chkdsk /r. if chkdsk not helped, again boot with windows 7 DVD and perform startup reapir.
After completing the repair restart and try to load the Mozilla. If any addons to be install, don't try to install all ad-dons at same time.
Regards Jinish.K.G|HCL Infosystems LTD