I split your question from the thread where you originally posted because that thread was quite old and related to problems with a different application.
Apple’s iTunes is a completely separate program from Apple’s iCloud for Windows. Uninstalling iTunes more than likely would have no impact on your current problem, but you should know that uninstalling and reinstalling iTunes will NOT cause you to lose your music or photographs.
According to this thread in the Apple support forums, the problem seems to be Apple’s rather than Microsoft’s, but it’s very common for companies to point fingers at each other in such similar situations. Seehttps://discussions.apple.com/message/26647924#26647924
I suggest that you try the steps given by “droyls” in the above-linked thread which I have copied below:
Thanks jab336 – I had this same issue but was able to follow your steps on Windows 7 (32bit) and have now got iCloud 4.0 installed apart from needing to do a system restart.
1. Sign out of iCloud.
2. Uninstall iCloud – did this using CCleaner
3. Removed contents of C:/Program Files/Common Files/Apple/Internet Services apart from 2 Shellxxxx DLLs that said were in use.
4. Ran Apple Software Update – found iCloud 4.0
5. Installed iCloud 4.0 successfully – restart required.
One major problem with the suggestion by “jab336” earlier in that thread is that I don’t know where you can find iCloud 3.1 if you don’t have the installer file for it on your computer already. “droyls” seems to have managed to install iCloud 4.0 without installing the older version first.
You can find CCleaner here –> http://www.piriform.com/ccleaner It’s safe to download and use, but please do not use the “registry cleaner” function. As with any downloaded program, be very careful to read the fine print during installation and UNcheck any options to install toolbars or search engines or the like (you may have to select “Custom install” rather than “typical” to see these options).
Finally, note that according to Apple, iCloud Drive will not work unless you’ve upgraded your iPhone/iPod to iOS 8, although most other iCloud features work at least with iOS 7.