A/C not working

I have a 2008 Aveo LT. The A/C has been working great. I parked the car at the airport long term parking for nine days when I returned the A/C is blowing hot. The light on the Button in dash is green, fuses all look good, when you push the button to turn it on you can hear the compressor kick on, bought a new can of r134 and started to follow the instructions. It said to attach the hose/gauge to the low pressure connection. When I do that the gauge reads in the red section. The instructions said to stop and seek professional help if that happens. The gauge reads just under 100 when a/c turned on. If you turn it off it reads just over 100. Any guesses to what might be wrong?

I would follow the directions and seek professional help. If the pressure is that high but it was working before, I suspect there is a flow restriction somewhere in the system.

("CAR OFF NOT RUNNING")Check the A/C pump to see if the clutch it clicking when the a/c is turned on (two people works best for this) if the wires to the pump are not broken or unplugged . This will make it blow hot air, or the pump clutch is rusted from sitting try to spray the clutch only tap on it little try to turn it try not spray the belt. When it turning retest starting the car check it BECARFUL of hot and moving part!! If the clutch really rusted badly will not move you might need a new or used A/C pump.