Can a car security system cause a car not to start?

I had best buy program a remote for me for the security system that was already in my car from a previous owner. Its been a about 2 months since but now all of a suddent my car wont start. It goes on for like 5 seconds and turns off. He mentioned something about how they unprogrammed the valet key, but this only just started happening. I had the fuel pump replaced and its got a brand new battery, any ideas?? Its a 2005 mitsubishi galant 47,000 miles

its possible. A lot of new models of cars have chips in the keys that will recognize them so that the key can’t be used to open a car that it doesn’t be long to or start it. you should check to make sure that the key is still programmed correctly.