I have a bunch of ancient motherboards with LGA1150 CPUs but I don't consider them suitable candidates for Windows 11 upgrades (even using rufus to disable TPM 2.0, Secure Boot, etc.). Some of my boards are CSM only, not UEFI, which can affect booting from Windows 11.
If this is your Dell motherboard (see photo), the footprint appears to be mATX and the PSU connections are standard 24-way and 4-way, so you could upgrade to a modern
low power mATX board with Intel or AMD CPU and still use the existing PSU (see CAUTION).
N.B. The 4-way 12VATX power connection to the mobo (white connector in bottom left hand corner of photo) is regarded as a bit weak nowadays. Modern motherboards usually come with an 8-way CPU power connector, others with an 8-way plus a 4-way feed for overclocking big CPUs.
CAUTION: Before upgrading with a new(er) motherboard, check the output of your power supply. Dell have a tendency to fit very conservatively rated PSUs of only a few hundred Watts, so there's no point getting a powerful new CPU or GPU. If the Dell PSU is rated at less than 200W, get rid of it before upgrading.
Another thing to consider is that if your computer is more than 6 years old, the PSU may be reaching the end of its design life. Now might be a good time to buy a new PSU with a higher power rating if you change the mobo. A typical low-end desktop PC without a separate GPU card will probably pull around 100W to 120W max and average around 50 to 60W. A gaming rig will require considerably more power.
The i7-4790 was released on May11, 2014, so the design is now over a decade old. You could try installing Windows 11 using rufus to create a compatible image, but I'd recommend buying a brand new system or a more recent mobo/cpu/ram combo than your current LGA1150.
https://rufus.ie/en/
List of Intel and AMD CPUs supported by Windows 11 22H2:
https://learn.microsoft.com/en-gb/w...ed/windows-11-22h2-supported-intel-processors
https://learn.microsoft.com/en-gb/w...rted/windows-11-22h2-supported-amd-processors