If you're replacing the motherboard and processor, you're presumably also replacing the RAM. A 10 year old machine also presumably could not handle today's NVMe drives, for example.

I'd question that it's worth trying to hang onto the case and cooling system, especially assuming you didn't put in some fancy liquid cooling yourself. And if the original PSU still is working, its days probably are numbered.

Anyway, you'd likely find it easiest to just do a whole new machine, though if you want to keep the new graphics card, it might be building yourself from scratch, or doing a prebuild elsewhere with the lowest-end card that you can simply replace.

Thanks.  So probably just better off to leave it on Windows 7 and let it roll.  It still runs good once it finally gets done with all it's start up tasks.  I spec'd and built a gaming pc for my son and it screams.  Guess I'll just go that route for myself.  I was hoping to at least salvage the cool looking case but oh well.  Thanks again for your response

Aurora R4 ALX case with 8700k and RTX 2080ti

I'm not one to recommend what mthrbrd or CPU to buy, but you could look into a micro-ATX (m-ATX / u-ATX) Asus MSI Giga AsRock etc with maybe a Gen10 Intel 6/8 core or AMD Ryzen (new Ryzen CPUs launch next week Oct ... post into that thread if u need help pulling out old parts & swapping in new ...

The CPU cooler can be re-used if u buy it a new retention ring kit from the Asetek Amazon store for whichever CPU socket u choose ... PSU can be changed out for an aftrmrkt type but if it still works u could try to squeeze another year out of it or so

Look into newer DDR4 memory also, & maybe a GTX 3070 GRFX GPU would be good

The fact is, Aurora R1-R4 has seen many owners swap in new mthrbrds / CPUs over the past 8 or so years, it can be done, it's just a desktop case in the end ... also see their Aurora sub-forum

the stock Aurora upgrade cooler is a 38mm wide Asetek, part# 01YGW (try eBay / google etc), others have tried the 49mm wide Corsair H80i GT / V2 etc

Thanks Casa-Ole.  I'll look into the mb.  Thanks for letting me what type of mb to look at as well.  Wasn't sure if it would be a micro-ATX or not.  

The only thing I would do with it at this point is ... install a SATA-SSD (as bootable C-Drive) and clean-install Windows-10 (if still a free upgrade). Maybe a 512gb ... to hold all Windows, all Apps, and a few games. Even a spare 256gb would work . The SSD will make it boot and run faster.

@Tesla1856 Yes, the free upgrade available through Microsoft's website still works - the upgrade will result in a activated windows 10 license and new product key.  Although, as a fair warning, if you ask your friendly Microsoft rep about this you could expect her to refer you to the EULA where it says successfully activation does not confirm a valid license, followed by a disclaimer that MS reserves the right to bill anyone taking advantage of the upgrade after Microsoft's advertised expiration date (although it's not happened yet to my knowledge). 

I forgot, here's (last week) an R1 + Asrock X570m pro4 / Ryzen 7 3800x > Aurora R1 DIY

Although, as a fair warning, if you ask your friendly Microsoft rep about this you could expect her to refer you to the EULA where it says successfully activation does not confirm a valid license, followed by a disclaimer that MS reserves the right to bill anyone taking advantage of the upgrade after Microsoft's advertised expiration date

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I've never heard of this

nor

Microsoft or Dell having a problem with you installing the normal (non-OEM) version of Windows (on a Dell machine) and therefore ... using the Windows-key that Dell burned into the BIOS.

AFAIK, the only thing YOU ARE NOT ALLOWED TO DO ... is to use that Dell-key on another machine.