It probably would create conflicts - and it would be a better idea to reinstall all of the OS and the Programs, but if you want to keep the files on the old Drive then its either put the old drive in the New Machine as the Main Drive and just Reinstall the OS before you even load it up - or put the New Drive in as a Secondary and copy the files over. I would choose the Latter.
A Knight is sworn to Honour. His heart knows only Virtue. His blade defends the helpless. His might upholds the Weak. His word speaks only truth. His wrath undoes the Wicked.