Do I have to rest my pc when upgrading?

[xSymph]

I'm upgrading my PC by adding a new mobo and cpu. Do I have to completely rest my pc? My internet is ass and downloading will be a complete pain.

 

[RARRAF]

No but you will have to completely reinstall the OS

 

[USAFRet]

I'm upgrading my PC by adding a new mobo and cpu. Do I have to completely rest my pc? My internet is ass and downloading will be a complete pain.

What OS? If Win 10, Read and do this before you change any parts:
https://support.microsoft.com/en-us/help/20530/windows-10-reactivating-after-hardware-change
http://www.tomshardware.com/forum/id-3164428/windows-build-1607-activation.html


What are the old and new parts? If there is a significant change, you will likely have to do a full OS reinstall.