Adobe Reader X, Acobat (2009 installation by Dell, Inc), and Windows Vista Home Premium: I successfu

Adobe Reader X, Acobat (2009 installation by Dell, Inc), and Windows Vista Home Premium: I successfully used Adobe Reader until last week when I could not open a bank statement. The notice stated that I should download Adobe Reader X which I already had on my computer. All of my pdf files have a green check mark on them; none will open. I tried opening pdf files on a thumb drive without the green check mark. does the green check mark mean the files have been archived or backed up? I cannot use Acobat. I have uninstalled and reinstalled Adobe Reader, Air, and Flash. I have checked the Security Settings for Medium, enabled scripts, and rebooted my system.  I have spent so many hours on this. I consider myself somewhat compute savvy. Please help me. Betty