I was planning on using my old HDD with windows 7 for a new build is this OK?

Will it cause any issues if im reusing my old HDD with the same OS on it and everything? Ive asked around on reddit and the consensus seemed to be that it would work fine. But i talked to a buddy at work and he said he thought that since everything in is going to be different that windows wouldnt like it at all.

If it boots it should work fine. The possible issues are:

1) that it either wont boot because of missing drivers, or

2) drivers from the old pc are making the boot longer or causing conflicts with the new hardware.

I would reinstall just to cleanup the drivers bloat from previous system.

So i should be good to go then?