How do I change where iTunes is installed to on Windows? For example, on my PC, iTunes shows up on my husband's user name but not mine.
When you install a software on windows it usually asks "install for this account only or for all accounts". It looks like your husband chose "for my account only". I do not know any option to change this later.
Last week I re-installed a program I had the same problem with. When it asked me, I then chose "for all accounts".
The user settings for the existing installation were not harmed.
The most simple thing to do is uninstall the iTunes and reinstall it selecting install for all users. Alternatively you can just install it under your username and it will likely realize that it's already been installed and may just allow the required files to be installed for your use.
It's possible though that the iTunes installed in such a way that it's only not visible to you but you can likely still run it. The simplest way to test this would be to go to, default on most computers:
on the admin account and place a shortcut to iTunes on your desktop. On the .exe for iTunes you might have to right click->Properties->Security and give the appropriate permissions to [your username]. If it works then you're done. If it doesn't it might be more tricky than that and it might not ever work without reinstalling.