Windows Vista of January 2009, it had been announced that Vista usage had surpassed Microsoft's pre-launch two-year-out expectations of achieving 200 million users. At the release of Windows 7 (October 2009), Windows Vista (with approximately 400 million Internet users) was the second most widely used operating system on the Internet with an approximately 19% market share, the most widely used being Windows XP with an approximately 63% market share. In May 2010, Windows Vista's market share had an estimated range from 15% to 26%. On October 22, 2010, Microsoft ceased sales of retail copies of Windows Vista, and the OEM sales for
Windows Vista editions development of embedded devices. Notes: Unlike previous versions of Windows, Windows Vista does not support compliance checking during installation; compliance checking previously allowed users to insert a disc as evidence that the operating system was being upgraded over a previous version, which would allow users to enter an upgrade license to perform a clean install. As a result, Upgrade versions of Windows Vista will not install unless a previous version of Windows is already installed on the machine to be upgraded. A workaround for this limitation was reported by Paul Thurrott, who stated that users should be able to perform