here is a simple hack to get iCloud control panel to work on Windows XP to give you synced access to Contacts, Calenders, Reminders and Bookmarks. It also can be used to set up your me.com mail. Photostream doesn't work.
I found a solution here, have written it up in clearer english and added details re IMAP support for me.com addresses here:
The iCloud setup hack for Windows XP:
- Download iCloud Control Panel for Windows- NOTE: old versions that work are still avaliable in my solution: http://42i.co/s/1ii
- Open iCloudSetup.exe file with WinRar or 7-Zip and extract.
- Navigate to and open the iCloud.msi or iCloud64.msi (for 64bit systems) with Orca.
- In the left table select LaunchCondition. Then change in the right table “VersionNT> = 600” to “VersionNT> = 200” and Save.
- Run modified iCloud.msi and install.
- Run iCloud Control Panel, located in the Windows Control Panel, and set up as you want.
I've had reports that you need to keep the files extracted from the .exe file in the same directory during installaton of the .msi file.