Monitor not working with new computer but works on my old one? Worked at the store?

[Luhrs]

I got a new computer and it was working at the store, it was working at the store. The graphics card is hooked up to a dvi and we're using the VGA, the store was using a VGA cord too. We didn't have a box and we had it in the backseat when we were coming home (I was making sure it wasn't gonna fall over, was sitting right next to it) and now it's not working, the monitor is working with my old comp (Which I'm using right now) I'm so confused and frustrated, can I get some help?

Specs:
EVGA Geforce 660.
Intel I5-4570.
Thermaltake 750w PSU.
LG W2240T 22-Inch Monitor (Black)
Crucial Ballistix 8 gig RAM.
MSI Military Class Z87.
Cooler Master Elite 430.

I don't think anything is loose, I think it has to do with the monitor but I dunno. I saw it working at the store (Tigerdirect to be specific) maybe the monitor doesn't support it?

To be clear, the store built it for me and installed the OS.

 

[SchizTech]

With the PC turned off and unplugged, open the case, pull out each stick of RAM and put them back in. Try to start again.

*there are clips at each end which hold the sticks in. Open them to pull the sticks out, then line up the sticks and press down until the clips lock to re-insert.

It sounds silly but it can clear a problem which can happen in which a static charge collects on the board.