|The general problem associated with that error message is that the computer does not meet the requirements to run windows defender offline.|
According to the Microsoft forum's post here windows defender offline requires your CPU to support SSE2, PAE and NX.
Unfortunately, looking at the specs on the DELL website, your computer will either use a celeron or a pentium 4 CPU. Although there were some models of Pentium 4 that supported the NX bit, they were not too common.
If you want to find out for sure if your computer supports the NX bit, you can download cpu-z. If you post the CPU name/model number here we can pull up the specs for you and find out if it supports the NX bit.
FYI some intel documentation may refer to NX as XD, which was it's former name.