Hey
cmosses ! I am not a windows person but fortunately I know someone who is

It is possible to upload a .zip file and extract it on your windows server. Just tested this and it worked. Here is the process:
Plesk > File Manager
There is a button at the top that says "Add New File".
You will need to ensure that you navigate to the folder where you want the file to be extracted to.
Then click the "Add New File" button
Here, there will be browse buttons where you can select the .zip file from your local harddrive.
Select the file.
Then there is a checkbox next to the browse button that says "Upload archive and extract it"
You will need to have that checked.
Then click the OK button.
It will upload and automatically extract the contents to the folder you had previously navigated to.
I hope this helps.
RandyT