There are many problems with your PC' HWID.
Biggest one is, that there is not 1 Hardware ID (H.W.I.D).
There is one per each device on your system. AS in, there is a Hardware ID for your Hard Drive (aka HDD-ID, many many people mistake this as HWID, since it's the most obvious and common of all hardware Ids.) another HWID for your SSD, another HWID for your printer, for your headset, for your Router, for your network adapter, monitor....and so on.
Open Device Manager. You'll see all your comp hardware and peripherals listed, right? Well, each of them has an specific ID. More so, there are over 1 hundred of specific Id's which are not Hardware ID's but system ID's in each computer that can be used to Identify that comp. And they are extremely easy to obtain. (Do not enter Privacy Laws here, cause they hardly relevant)
Then, get 5? of them. Turn them into a fingerprint. That's your machine ID.
Beyond that, it's been known for a long time along the botting scene that Blizzard was using a machine ID to flag accounts for checking. Obviously not for straight up banning accounts using that same Machine ID, but once you create a new account in there , it will be under heavy scrutiny.
That's the reason for the instabans after having been catch with a bot farm and not making a full reformat of your pc.
Ignore folks that say otherwise. Sadly there are people who can't value other people experiences, and what happens to them is the one and only truth. Example: big botter Timmy which was banned in his grand 1 account, bought another on the same comp, and lived happily ever after without bans. Therefore point proven? Blizzard doesn't ban by machine ID? Nopes. It just proves those people as retarded and dumb.
To resume this, Blizzard wouldn't be as stupid as to check 1 device ID for fingerprinting your machine. As stupid as many people pretend them to be, they aren't. And it will be extremely difficult for you (next to impossible, without serious leaks) to know which specific HWID's and other system GUID are being used.
Best advice I can give is to reformat your PC, and download a new game installation from a new account ( after having changed your IP, Mac ID and HDD-IDs)I never thought payment method were being used since that REALLY has some privacy issues. But they still could, for all we know.
That might be enough to "clean" your machine, or not. But it should be a good approach.