New build, old Windows?

[lazereagle]

I'm currently ordering all the parts to rebuild my PC from the ground up. But I'd like to keep my old hard drives/SSD, and most importantly, keep my old Windows installation. I've been buying upgrades since XP, and I'd rather not buy a whole new version of 7 or 8 (especially since I'm a student and I got the upgrade versions for free).

So, if I simply take my old system drive and plug it into the new mobo, will I be able to download all the new drivers etc, or will I be completely screwed? And will my license transfer? I'm pretty sure the student license can be installed on 2 PCs with the same key.

For reference, here's my old and new setups:

OLD
Mobo: ASUS A8M2N-LA (Micro ATX AM2 board from an old HP pavilion)
CPU: Athlon 64 X2 6000+ (3.0 GHz)
4GB DDR2
XFX Radeon HD6850
LB Blu-Ray reader
System drive: 120 GB SSD
Data drive: 1TB HDD
Backups: 1.5TB external USB HDD/ 1.5 internal HDD combined into single Storage Space
Windows 8 Pro

NEW
Mobo: ASUS P8Z77-M Pro
CPU: Intel i5-3570K
16GB Kingston HyperX Blu
XFX Radeon HD6850

Same drives, and hopefully the same Windows!

 

[Deemo13]

The license might not transfer if the OS is OEM. You would have to reinstall when installing a new motherboard. Sometimes you can get away with it.

 

[lazereagle]

So what's the worst case scenario? If I plug in the old drive and start it up, it just won't boot, right? I won't wreck my drive, will I?

 

[Deemo13]

Well, it will just start blue-screening. You would just need to reinstall.

 

[lazereagle]

As long as it detects that Windows is already installed, I should be able to use the upgrade version, right?

 

[Deemo13]

You might, but I cannot be sure. If you have it, its worth a shot maybe.