Microsoft is to "up the ante" on tackling unlicensed business software after its latest figures showed one-third of customers still run counterfeit software.
Microsoft is hailing the success of its "Keep IT Real" crackdown on counterfeit software one year on from its launch, citing a 3.8 percent drop in the rate of fake Windows XP, to 12.9 percent.
But more than 8,300 pieces of counterfeit software have been found on UK business customer premises since July last year.
Michala Alexander, UK head of Microsoft's anti-piracy unit, admitted illegal software use is still rife among medium-sized businesses — generally those with more than 100 employees but fewer than 1,000.
She said: "We are still seeing a large number of businesses in the mid-market using large amounts of counterfeit software. It is still very much a problem."
Most of the illegal software discovered was high-quality counterfeits, and Alexander said: "We have even seen one case where the customer actually paid more for the counterfeit copy than a genuine copy."
Microsoft does not take legal enforcement action against customers found to be using illegal software, beyond making the customer pay to replace the counterfeit products. Instead, the enforcement action is targeted on the channel and the resellers who are distributing the fake software.
Alexander said: "When we find it in a customer site we will go after the reseller as well. We are fully committed to ridding the channel of pirated copies. We will be upping the ante on enforcement."
In addition to more enforcement action Microsoft will also be keeping a close eye on the counterfeit market for Windows Vista over the next 12 months.
Alexander said: "We will be watching the activation process we have built into Vista closely but we haven't yet seen any counterfeit copies of Vista."