Microsoft has warned Windows XP users against using a hack that tricks the company’s servers into applying security patches to the now-unsupported operating system.

The workaround first appeared on a forum website called Sebijk, which revealed how making a small change in XP's registry will fool Microsoft’s upgrade servers into thinking they are applying security patches to newer versions of Windows.

However, Microsoft has stressed that XP users exploiting the hack may encounter various problems and would not be fully protected.

In a statement to V3 Microsoft said: “The security updates that could be installed are intended for Windows Embedded and Windows Server 2003 customers and do not fully protect Windows XP customers.

"Windows XP customers also run a significant risk of functionality issues with their machines if they install these updates, as they are not tested against Windows XP.”

It is not clear how long the update hack will remain usable now that Microsoft is aware of its existence.

Microsoft said that XP users who are concerned about the security and functionality of their PCs should upgrade to a newer and supported version of Windows: “The best way for Windows XP customers to protect their systems is to upgrade to a more modern operating system, like Windows 7 or Windows 8.1.”