Vista was Microsoft's most recent Windows operating system released in 2007 with the goals of improving security and manageability. While it enhanced security features like user account control and BitLocker encryption, Vista was also not compatible with many older PCs and performed more slowly than the previous Windows XP according to reviews. As a result, Vista failed to gain widespread adoption by users and businesses, contributing to Microsoft's first revenue decline in years. The company is now rushing the replacement Windows 7 to market in hopes of better success.