Ya lost me... why would you need a new HD ? Are you sayinbg you have no place to back up your data to ? That is scary.
Is this Widows 7 or Win 10 ?
Windows 10 is transferable unless you bought A dell or something w/ Windows preinstalled
4. Transfer. The provisions of this section do not apply if you acquired the software as a consumer in Germany or in any of the countries listed on this site (aka.ms/transfer), in which case any transfer of the software to a third party, and the right to use it, must comply with applicable law.
a. Software preinstalled on device. If you acquired the software preinstalled on a device (and also if you upgraded from software preinstalled on a device), you may transfer the license to use the software directly to another user, only with the licensed device. The transfer must include the software and, if provided with the device, an authentic Windows label including the product key. Before any permitted transfer, the other party must agree that this agreement applies to the transfer and use of the software.
b. Stand-alone software. If you acquired the software as stand-alone software (and also if you upgraded from software you acquired as stand-alone software), you may transfer the software to another device that belongs to you. You may also transfer the software to a device owned by someone else if (i) you are the first licensed user of the software and (ii) the new user agrees to the terms of this agreement. You may use the backup copy we allow you to make or the media that the software came on to transfer the software. Every time you transfer the software to a new device, you must remove the software from the prior device. You may not transfer the software to share licenses between devices.
As for Win 7, if it is OEM version, it will install easily on a Motherboard of same name.... I have done it many times ... MS treats it as a warranty replacement. If your mobo failed and you replace it, a call to MS usually resolves the problem.
In addition, it's not about not being able to install it .....it's about being able to activate it. Let's say you manage to get it working updating drivers and the occasional conflicts are not all that irritating ... you still can't activate Windows. When you run Windows update ... it will see the new MoBo .... and **if** the MoBo replacement is a problem, it won't activate. So it doesn't matter which way you do it ... fresh install or the wa you are trying, int he end you are in the exact same situation.
A fresh install is quite easy
1. make sure you have all your product keys. If you don't run Belarc Advisor and it will produce a file listing them that you can save ti disk and print
http://www.belarc.com/free_download.html
2. Follow the tutorial for your OS:
http://www.sevenforums.com/tutorials/1649-clean-install-windows-7-a.html
http://www.tenforums.com/tutorials/23354-clean-install-windows-10-directly-without-having-upgrade-first.html
Youve been a big help.