Help on replacing motherboard

[Ahoo__109]

My current motherboard only has 1 PCI express 2.0 x16, and I am wanted to get a new one with 2 PCI 3.0 x16.
If I want to buy a new motherboard and replace it for my old one, will I have to do such things like re install windows and and such, or will it run just like before, but with a new motherboard?

My specs:
Intel i5-4460
MSI AMD R9 380 2GB (MSI Radeon R9 380 R9 380 2GD5T OC 2GB 256-Bit GDDR5)
2TB HDD + 120GB SSD
MSI H81M-E33 motherboard (Micro ATX)
8GB DDR3 1600MHz RAM
NZXT s340 case

I'm new at building / maintaining PCs so I might need to noob-worded answers, thanks.

 

[noriel]

You have to reinstall..your OS wont recognized the new hardware

 

[Greg Gregorich]

if the mobo chipset different you wanna sweep more software (programs)as possible like video,audio,drivers.storage controllers.

 

[Ahoo]

ok well looks like I might as well buy a new computer than replace a motherboard. I was just concerned that I don't have much room to upgrade since my current motherboard only has 2 ram slots up to 16gb of ram, and only 1 pci e x16 2.0.