What kind of car? If it sounded like a grinding noise coming from one of the vents it could be an ac actuator, and based an it not blowing cold air, probably the temperature ac actuator.
Oh and for the windows, all the windows stopped working at the same time? If so can you raise/lower them with another switch?, if so its your master window switch. If not its a fuse or short. Hrmmm...just noticed you said manually, that makes no sense that all manual windows would stop working at the same time, manual means it would have been some mechanical failure and to have multiple windows go out at the same time is just very unusual.