Microsoft’s antipiracy plan announced this week is a slap at a multimillion dollar problem, but it leaves a number of questions especially for volume licensing customers who will have to devise new administrative and management plans to ensure their software doesn’t get crippled.

Microsoft’s Software Protection Plan (SPP) is used to validate the use of genuine — that is, paid for — copies of Windows and to partially cripple systems that don’t pass muster. Microsoft has stepped up its attacks on software pirates, including 26 lawsuits it sparked in July.

“In the business market, [SPP] is a mechanism that conceivably will reduce the leak of volume licensing [product activation] keys, which is believed to be a big facilitator of piracy, but the flip side is that there is a burden for business customers," says Joe Wilcox, an analyst with Jupiter Research. “And that is going to be more cumbersome management."

As Microsoft nears completion of Vista, slated to ship to corporate users next month, SPP is one of a number of volatile issues churning around the new operating system. McAfee and Symantec last week took Microsoft to task over new features in Vista to protect the Windows kernel, a move the two security competitors say harms their products and ability to compete.

The feud dates back two years when Microsoft turned on its partners and began offering competing products. But experts say Microsoft will have to give in eventually to keep competition fair.