Can a registery cleaner or antivirus delete important files?

my microsoft office 2003 small was deleted and my computer won't work good and It keep on saying install microsoft office 2003 small and I don't have the disk can antivirus or registry cleaner delete it is there any sulution to this please help

Can a registery cleaner or antivirus delete important files?antivirus download

It wasn't an anti-virus. You should re-install it.