May have to turn off secure boot depending on your win7 usb.

 Secure boot must be off and Legacy CSM ON.

Windows 7 installer cannot remove a windows 10 partition so you will need to use WINPE and Diskpart to clean the disk.

WINDOWS 7 does not support USB3 so you MUST USE a USB2 DVD to do the install

My universal installer for 7 or 8 or 10 is

https://www.bestbuy.com/site/lg-8x-external-usb-2-0-blu-ray-disc-double-layer-dvdrw-cd-rw-disc-rewriter-black/9243009.p?skuId=9243009

OEM System Builder Disks are Required and the Skylake Windows 7 Dell disk is a specific media.

<ADMIN NOTE: Broken link has been removed from this post by Dell>

DELL SKYLAKE WIN7 PRO ONLY

speedstep!

Great post and extremely helpful!  But I can't fathom why anyone wants to go back to Win 7(?) ~ perhaps it's a matter of apps that only run with Win7?

All that aside, your reply is outstanding and ~ as many times as I've installed Win7 ~ most of your comments are things I didn't know!

Thank you and Thumbs UP

Anthony

If windows 7 is required a newer system with 32 gigs or more of ram should have no issues running windows 7 as a Hypervised Virtual Machine.

But since all new hardware is 64 bit and 10 only I fail to see the reasoning behind using 7 when it Dies April 2020.

USB2 media is required because USB3 is not native to windows 7.

Whether Flash Drive or DVD drive it MUST BE USB 2.0 or it will fail.

hello and good day to you.,

can I ASSUME , that all your data is backed up and no lost licenses or apps? (on the old HDD)

3050 is not new, 2017? but why  so small memory and hdd>?

what midia is it sure USB but is the stick built fresh with mS, w7 ISO> from Microsoft.com  < MEDIA MATTERs !@

Some USB ports may be dead USB3 are CLASSIC sure slipstreams works sure, but do you have 3 days time wasted learning how  to do that? hah.

So IN BIOS you got lost sure, but spend time time there, spend 30 full minutes, after no 2 BIOS are the same

and learning what is there NO tops the list, even upgraded it. sure.

Secureboot on kills dead the CD/DVD drives and USB and sure all but SSD0  or HDD0 boot drives.

so we must  turn that off first, and other places too,  like usb legacy mode on if seen.

some newer BIOS have CSM mode and too kills Secureboot off.

what version BIOS you have I could never guess, nor know them all 20 versions per PC, for 10 years.

The BIOS (many) can even turn off USB ports (like at the CIA>?) so nobody can use them, so we look there.

also use f12 key , power on ,hammer F12,tap tap bam you be in BOOT on the fly menu I call it

see you USB installer now>? try all USB ports yet, does other PCs allow you to see that USB STICK

test the stick on other PCs/ im sure you did.

Also Best is full erase the ODD hDD so w7 does not go NUTS.

Windows 7 setup .exe , if it thinks data can be damaged it BALKS !  (by design) (unless upgrade mode but is not this downgrade)

this is my 3020 and is all there, on newer PC  BIOS gets even more powerful with more choices.,

w7 supports ends JAN2020 , is this w7 application that only runs on w7 why go backwards and all the risk that places you in.? tell why, the answers maybe surprising,

Im no expert on 2017 dell PCs,not at all and the BIOS is far more advanced than mine. 4years newer.

Id for sure still use GPT format for w7  in CSM mode. (keep the ethernet cable connected so drivers load better and faster at install time.  W7 fresh from MS is royal PAIN,  with over 350update after an install.

Id use there most Fresh ISO from them and cross fingers it does not take 2 days to gain updates, w7.

The updates work best if w7 IE11 is installed first. or it goes nuts. (w7 is a horror now,,, can run 2 hours non stop talking,  only on horrors) but will run if patient sure.

if only issue is privacy gee, run O%O shutup10.  and end that simple fear. (run that and w10 is w7)

if w10 updates are painful, run w10 pro and use GPeditor,  ask. how. (the art of delaying buggy updates 101)

https://www.oo-software.com/en/shutup10

You can install Windows 7 with USB 3 (and uefi) but you'll have to slipstream the USB drivers into the installation media.