Hi Chrissy and welcome!

When checking my ip through the internet it is completly different to the ip which states when looking on my computer.

It is important to understand that wireless routers are two or three SEPARATE devices. The router, the wireless access point (WAP) and perhaps a 4-port Ethernet switch. They may be in the same box, but in networking, they are separate devices.

Your ISP assigns an IP to your "gateway" device, typically the cable/DSL modem. The gateway is the device that connects you to the Internet, and supports only one network device. That can be a PC, or a router. A router connects two networks, in this case the Internet and your network. The WAP connects to the router just as a print server or other "wired" computers would through the 4 Ethernet ports of the switch. And the router would assign the WAP an IP too. So you may be seeing the IP the router assigned to your computer, the WAPs IP, and the IP assigned by your ISP - the one the world sees.

i recently reinstalled windows on my computer, and wondered if that had anything to do with it.

The IP of the computer might have changed, but if your network (and other computers) on your network stayed connected to the Internet, then that would be the only change. That is, your ISP would have no reason to give you a different IP.