<p>Microsoft's planned upgrade of Hotmail users to its new Outlook.com service hit a snag yesterday, with numerous reports of users being locked out of their accounts.</p><p>The problem seemed to affect existing Hotmail users that have recently upgraded to Outlook.com, preventing them from accessing their emails when they signed in via its desktop and mobile sites.</p><p>According to our sister site IT Pro, non-Hotmail users that have signed up for Outlook.com accounts do not appear to have been affected.</p><p>Hotmail and Outlook.com users took to social networking site Twitter to express their frustration at the service trouble, which is thought to have lasted for several hours.</p><p><a href="http://www.cloudpro.co.uk/saas/email/5325/hotmail-problems-blight-outlook-upgrades">Keep reading...</a></p><p>Read also:</p><p><a href="http://www.latinospost.com/articles/12947/20130225/microsofts-updates-hotmail-users-outlook-locked-out.htm">Microsoft&#039;s Updates Hotmail Users To Outlook, Some Users Locked Out Of Their ...</a> (Latinos Post)</p><p><a href="http://www.brantfordexpositor.ca/2013/02/23/new-outlook-is-hoping-less-is-more">New Outlook is hoping less is more</a> (Brantford Expositor)</p><p><a href="http://investorplace.com/2013/02/microsofts-outlook-on-email-looking-better/">Microsoft&#039;s Outlook on Email Looking Better</a> (Investorplace.com)</p><p>Explore: <a href="http://news.google.com/news/more?ncl=dvQm6rnOYvKjIFMAaXedRr51u0TRM&ned=us">22 additional articles.</a></p>