Yes i used same phone and pc to transfer files when i was on miui.Did you use this pc in the past to transfer files and worked?
In the past i had the same problem because widows didn't have the mtp drivers installed.
Give it a try, you can check the Optional Features installed on your pc, if it's not listed under the installed section then try to install it.
I tried installing mtp drivers, but still cant connect.
This is so weird