Why won't my car start after not being used for 1 week?

Chance is your battery might be flat. Do you headlamps etc come on and stay on? Have you tried charging your battery? If you dont have a charger you can try bump starting it, by pushing it with a friend and dropping it into gear, or roll down a hill and try, normally in second. If you have an auto, you have to charge it.

If that works and you plan on leaving the car standing for a month again, get a friend to pop round and start it every week or disconnect the battery. Quite easy to do, just need a spanner and lie the cables to the side of the battery. When you are back just connect it up, might take a couple of turns but should start. Hope this helps.