Q: How do I transfer a file from my Windows 7 laptop to my Ipad Air?

Hi

A few more information would be helpful.

What kind of file do you have?

What do you want to do with it?

The easiest way could be using dropbox or onedrive. Or do you want to edit the file on the iPad?

Mp3-Files are also files. And with iTunes you can copy these ones to your iPad too.

If you just copied it to the iCloud Drive folder in Windows Explorer, then you can simply open the iCloud Drive App on your iPad and look for it there.

If the file is large it may take a minute to sync.

Glad it worked.