Hackers have cracked a security feature in the forthcoming x86 OS X operating system that is designed to prevent the software being run on non-Apple hardware.

Apple is in the process of swapping out its existing IBM PowerPC processors for Intel's Pentium processors. It has previously said that it will prevent the version of its operating system for so-called Mactel computers from running on non-certified hardware such as a computers made by Dell or HP.

While the first Intel-powered Apple computers will not be available until the middle of next year, the computer maker last month started shipping Developer Transition Kits to allow software developers to test their applications for the new hardware platform. 

Several developers have reported that the kits contain the Trusted Computing Platform (TPM) security chip that prevents the software from running on non-Apple hardware.

Apple declined to comment on the existence of the TPM in the kits.

The security check in the software has now been circumvented.

The method works only on systems with processors that suport the SSE2 or SSE3 instruction sets that are found in processors from Intel since 2001 and AMD since 2003. It requires a fairly advanced installation process that will be hard to understand for regular computer users.

There are several legal caveats for using the software. Most importantly, the method relies on pirated copies of the OS X operating system which are widely available through the file sharing networks.

The hack is a moral defeat for Apple, but few users will exploit the hack, predicted Martin Reynolds, research fellow at analyst firm Gartner.

"Most PC users aren't interested," he told vnunet.com, adding that they would be unable to get support from Apple if they ran into any problems.