attempting to login to windows live using powershell but getting an error about cookies which is weird because I am able to login just fine when done manually.
this is the exact message "cookies must be allowed"
Yeah, the problem here is that while a web browser automatically accepts and sends cookies, Invoke-WebRequest does not. The examples in Invoke-WebRequest's help file shows an example of accepting and re-sending a cookie. Since you're not using a web browser, you have to manually code some of the plumbing a web browser normally provides.