500GB HDD full, where to go from here?

I'll be getting another HDD, however my ideal situation would be getting a new ssd and just putting windows on the ssd and have both HDD's for storage and in this case just the new HDD.  Most people are saying just connect the ssd and install windows, I'm confused as to how the new windows on the ssd can relate to all the files on the old HDD.

Well unless you get a large SSD, after formatting and installing the OS and a few programs there won't be too much room left on it. 

While an SSD is nice for a speed boost for large amounts of storage, which you need, it doesn't quite cut the mustard. Its too expensive 

What you would do though is get the SSD and use the included software or some.you downloaded to migrate the OS over to the SSD. This does cause problems though. A fresh install would be best. Then you'd remove Windows from the other drive. 

80-120GB is fine on Windows 7. I still have about 30GBs left. I just put programs which I need fast on the SSD and the rest on my HDDs. It all really depends on the user from what I understand.

SSDs. Get a bunch of them and run in raid0.

No I'm not saying that the SSD won't hold Windows or anything like that.

What I'm saying is even if you only put the bare minimum on the SSD and removed Windows from his HDD he would still be left with ~100GB of free space. That really isn't that much and he would most likely fill it up and be in the same situation again relatively quickly. 

That is why I suggest he buy a 1TB mechanical drive instead of the SSD or if he can swing it a mechanical drive and the SSD. 

Wait. Nevermind. Just realized he said he was going to buy a mechanical drive and an SSD. Oops. 

Right hold on a minute guys, step by step what should i do.  Should I just connect the SSD and do fresh install then connect the 2 HDD's.  What problems will arise, will I have to re-install programs etc. And as well what do i do about steam, the current hard drive with steam is full, will i continuously have to download them to the drive that is full then and then move them to the new drive with a method on youtube i saw.  Its all really confusing and can have drastic consequences if done wrong 

I believe its mklink is the method i saw on youtube

Here is what I did, copied all my stuff to a large hd, disconnected the boot hard drive and installed the ssd, loaded it up and transferred settings, easy as pie, then hooked up the old boot drive while booted up to the ssd and unmounted it and completely reformatted it so it does not have a boot sector, no active partitions.

Reinstall and use to your digital joy, easy!

So backup all your files to a separate drive then format the existing drive after setting up os on ssd.  Then restore everything back onto formatted drive?  DO you have to do this or can you not just delete the old windows folder?  What I really want to know is when you fresh install the os onto the ssd and reconnect the HDD, will everything be as before?

You would have to clone the drive to get it back exactly, But it is doable, But you may have to keep the 500 as the boot drive to do it that way, just weed out the windows old folder a small bit, but you will not be able to remove any boot functionality from the hard drive, but it would still be fast enough booting to make your mind sweat.

Can you not remove the boot functionality without formatting by deleting certain files?  I don't mind if the boot functionality is still there, is it not just a matter of re-adjusting the BIOS to boot from the SSD?