"How does a Windows user upload to my public directory on iDisk?"
Uploading to an iDisk public directory is basically the same for both Windows and Mac users. For it to work properly you need to have the correct permissions set and there may be a password required from the iDisk account holder. Here's how to upload from Windows or Mac to a public directory on iDisk:
The first thing you need to do is make sure you have the proper permissions set in your MobileMe account. For public uploading to be enabled, you need to select Allow others to: Read and Write. Password protecting your public folder is optional, but if you are going to allow uploading I strongly recommend using a password. Make sure this password is not the same password you use for your MobileMe account so that you don't risk allowing someone to take control of your account.

When you tell people where your iDisk is, send them the link to:
http://public.me.com/username (replacing username with your MobileMe username)
When someone arrives at this iDisk page, they will be prompted for a username and password. The username will be the word public. The password is the one you created when you clicked the Set Password button.
When connecting from Windows, Mapping a network drive is also an option. To map a network drive to iDisk, open Start > Computer and click on the link to Map Network Drive using the same URL and username and password.
