In browser under downloads you should see it. You then will need to use a burner utility to burn it to a DVD or use a utility that will erase a 8GB or larger USB stick and make the USB stick bootable.
This will install Windows 10 clean to computer. You will want to backup any important data that you might have on this computer first before installing Windows 10.
After installing Windows 10, unless you have a Windows 10 key or can get Microsoft to grant you an activation, it will be an install that will keep telling you in the lower right corner that this version of Windows is not activated and click to activate. When clicking to activate you need a key for Windows 10 that Microsoft will approve for Windows 10 use. I don't believe a Windows 7 key can be used anymore for Windows 10 and so after this you will likely have to BUY A KEY for Windows 10 from Microsoft to activate it. However if Microsoft will grant you an activation by chatting with their support then you can get one free. If they say sorry we cant do that though, then your looking at the cost of a Windows 10 key which last I checked was $99.99 (USD) for Windows 10 64-bit Home Edition.
Cheaper route would be to contact Dell and get the System Recovery Media for that computer which would be around $35 + shipping (USD) for whatever OS version the system was sold with, which should be a 64-bit OS according to Google searching that model which came with 4GB RAM. A System with 4GB RAM should have been sold with 64-bit OS to make full use of the RAM as for 32-bit OS can only use 3GB of 4GB. If System was sold with lesser than 4GB RAM then its more likely that its a 32-bit OS system.
