I bought a Brother MFC 255CW Printer and it worked perfectly fine on my Windows laptop and my Mac computer at firt. After changing my wireless connection (I got a new network name and password) the printer prints but a day after I ask for a print. It takes forever for the print to come out (sometimes over 24 hours). It still works with the Mac and it will even scan to my windows laptop but printing is not possible right away. Can someone please help!

This can have several reasons, network or firewall configuration of your laptop, virus-scanner, network-configuration of the router or AP.

But let's start with the easiest:
Delete the printer from your Laptop, best is if you uninstall the brother software too(personalized configuration will get lost); Reboot the Laptop; deactivate Virus-scanner and Firewall; reinstall printer+software; try printing; If okay reactivate firewall and antivirus; try again.
The network troubleshooting will be complicated: please provide additional information like : Printer-IP (fixed or DHCP?); IP of your Laptop (same segment?); Router-Model and cofiguration (Firewall between LAN and WiFi?).
But try the driver thing first!