You can click here to update your Latitude drivers. You can also click here for troubleshooting slow wifi connections.

Also check.

Distance from the router: 

• Background programs:

  Programs running in the background on your laptop can also consume bandwidth and slow down your internet speed.

  Run network troubleshooter:

  Windows has a built-in network troubleshooter that can help identify and fix problems

  To receive assistance from Dell chat support, they need to verify the warranty status and ownership. Then you must troubleshoot with them.  Click the "Get Help Now" icon on the right to start a live chat session. If already out of warranty, click here for the Dell out of warranty offering.
  

I have registered the machine with Dell and I have support. I was more speculating as the Windows is a fresh install on a new SSD as the original one was wearing out already.

Guess its time for a fresh install of Windows, again