How can I tell how old my desk top computer is?

Welcome : well if you want to know, when the computer was built it

My guess is that, information is showed in a sticker outside

of the "Tower. if is a desktop" same apply for laptops

or you, can ask to. The computer manufacturer

which built up the computer

Now, if want to know. When the operation System

   was installed : Follow these steps below

In the Windows search box in the taskbar, type cmd and click - Enter

once the Command Prompt screen, has opened : type systeminfo.exe

and hit enter. Scroll down until you see "BIOSVersion”

check the date listed. Hope this helps,.?

How can I tell how old my desk top computer is?

Look at the invoice.