After 12 years, Microsoft is ending support for its Windows XP operating system tonight at midnight. After this point, the company will no longer offer security updates and technical support for the OS.

If you are still using XP, Microsoft urges you to migrate to a “modern operating system” like Windows 8. Support for Office 2003 will also end today, April 8.

Microsoft launched Windows XP on December 31, 2000 and stopped selling the OS at retailers June 30, 2008. On October 22, 2010, Microsoft stopped selling Windows machines with Windows XP installed.

The end of support for Windows XP is proving problematic for some larger institutions. For example, thousands of computers in the Connecticut state government system still run Windows XP. The hard drives on the computers have tax information, inmate lists, and other various regulatory files, all of which could become vulnerable to security breaches over time.

Microsoft says enterprise customers (companies or institutions with 500+ employees) can reach out to Microsoft to learn how they can mass-upgrade their network of machines.