go to safe mode and try to remove (sorry-i shud say uninstall) it.
u can do so from addremoveprograms or thru the 'uninstal' from the srat menu shortcuts.
if this fails, i think u shud agn go to safe mode, delete the program folder, search for 'panda' on your pc, remove those file. just delete them.
then download and use 'ccleaner' from
www.ccleaner.com to clean ur invalid registry entries and other pc junk. dont worry, ccleaner is safe.