It usually tells more than that but iTunes install issues are usually due to antivirus suites or malware. I can't tell given this amount of detail.
Try this. Install iTunes with Ninite.com. Here's why:
Trying to install ITunes, get all the way through and then it tells me it cannot install because it has encountered errors and saying my system has not been modified. I am running Win 10 all updated to the latest version on a HP Pavilion PC.