How can I make my iPhone 5S go back to charging from my Dell Windows laptop USB port?
I solved this problem by disabling the non-USB 3.0 device in the Windows device manager. For some reason, iPhone is not happy when a non-USB 3.0 device is active. I'll leave it to someone else to explain exactly why. 

Anyhow, the fix is:
1) Open Device Manager
2) Find the "Universal Serial Bus controllers" section
3) Find the USB device that does NOT seems like it's a 3.0 device (in my case it was called "USB Composite Device")
4) Right click on that device, and click "disable". 

Voila, my iPhone charges and connects again.

See below what my Device Manager window looked like after I disabled the non-USB 3.0 device. 


Hope this helps someone.