If you’re in a situation where it appears to take forever to open a PowerShell prompt, Internet access might be the problem.
The easiest resolution at this point appears to allow Internet access to the machine. If that is not possible, you can disable the check for the publisher’s certificate revocation. You can do this from Internet Explorer (or Control Panel, Internet Options) by clicking on Tools, Internet Options. Under the Security section of the Advanced tab, uncheck “Check for publisher’s certificate revocation”.
NOTE: These type of security features are in place for a reason. Take caution when considering disabling these.