How do I identify what model Dell computer I have .

Hello Again,
I’ve been looking on dell support trying to find what model I have
I entered service tag number but got message nothing found, maybe it’s too old ?
Also when I look in my computer specs I have question mark by computer icon, driver not found
Any help gladly appreciated
Really like windows 10 so far

Should be some kind of tag or silkscreen that states the model on it.

Dell Service Tags will identify your computer's model.
https://www.dell.com/support/home/en-us?app=drivers

In this case, you have an Optiplex 9020.

Piccy:

According to the service tag number on the rear of the case, you have THIS Dell OptiPlex 9020 Small Form Factor which was originally purchased in November 2015 in the U.K. and came with Windows 7 or Windows 8.1 64-bit.

Thanks that’s great

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Hello no tag for some reason many thanks

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A great help great forum so interesting and helpful people

You may have misread the "service tag" number and not entered it correctly.
You can also check by using the "express service code" number.

By the way, I have 3 Dell OptiPlex 9020's with the larger mini tower case.
They all run in dual boot mode with Windows 7 and Windows 10 64-bit.

Many thanks
Mine has 2 hdd windows 10 is freshly installed on 1st but I believe nothing is on the 2nd