Because you want Windows 7 you of course will have to chose form an older line of laptops. I prefer the Dell Latitude series of laptops since they are (from Wikipedia), "a business-oriented line, aimed at corporate enterprises, healthcare, government, and education markets."
I have had nothing but Dell laptops and several were Latitudes. All worked very well, but then again, I know what I'm looking for...
Having said that, the Dell Latitude line of laptops that are the "latest" and support Windows 7 are the models from 2017. And they are as follows:
7480: 14.0" Ultraportable (7th gen Core i3/i5/i7)
7389: 13.3" 2-in-1 Ultraportable (7th gen core i3/i5/i7)
7380: 13.3" Ultraportable (7th gen Core i3/i5/i7)
7285: 12.3" Convertible Ultraportable (7th gen Core m3/m5/m7)
7280: 12.5" Ultraportable (7th gen Core i3/i5/i7)
5580: 15.6" Mainstream (7th gen Core i5/i7)
5480: 14.0" Mainstream (7th gen Core i5/i7)
5289: 12.5" Ultraportable 2-in-1, (7th gen Core i3/i5/i7)
5285: 12.3" Convertible Ultraportable, detachable keyboard (7th gen Core i3/i5/i7)
5280: 12.5" Mainstream (7th gen Core i5/i7)
3580: 15.6" Essential (7th gen Celeron/Core i3/i5/i7)
3480: 14.0" Essential (6th gen i3-6006U/i5-6200U 7th gen Celeron-3865U, Core i3-7100U/i5-7200U-7300U/i7-7500U)
3380: 13.3" Essential (7th gen Celeron/Core i3/i5/i7)
3189: 11.6" Education Convertible 2-in-1 (Pentium N4200 Intel 7265, Celeron N3350)
3180: 11.6" Education (Celeron N3350)
From Wikipedia:
Dell Latitude - Wikipedia
From that list I'd chose one with an i7 quad core CPU if you can. You can use the picclick.com website to help find the most suitable and cheapest on eBay. Then again, I don't know if you're located in the U.S. or whatever that the picclick website supports or not.
These look nice:
"dell 5580" in All Categories - PicClick
"dell 5480" in All Categories - PicClick
Note that if you do buy a used laptop it will more than likely need a new battery. If so you want a genuine Dell OEM battery. If the laptop needs a power adapter you also a want genuine Dell OEM power adapter. Reason is for safety and the reduced risk of damaging your laptop.
You can always update the hard drive yourself.
The reason why these 2017 line of Latitudes support Windows 7 is simply because they offer Windows 7 drivers at Dell's website. The 2018 line of Latitudes on up only support Windows 10 and above drivers.
