Many PCs are still not being updated to deal with the infamous Conficker worm, according to security experts Sophos.
According to the company's data, more than 10 per cent of people have failed to install the Microsoft M08-067 patch.
"We would have hoped that computer users would have woken up to the threats and installed this patch," said Graham Cluley, senior technology consultant at Sophos.
"Not only has the patch been available since last October, there's also been so many reports on the potential consequences of failing to patch. This is pretty depressing news.
"Of course, we can't extrapolate this to mean that 10 percent of all PCs around the world aren't running the Microsoft patch, but it certainly tells a sorry story for a notable percentage of those who took our test.
"It appears that the percentage of computers not patched against the exploit used by Conficker is holding steady."
Although the Conficker worm has perhaps not had the impact that some suggested – especially on the 1 April date that had catapulted it into the headlines – the worm remains a key threat to computers.
Both the Ministry of Defence and Sheffield hospitals have been high-profile victims to the infections, along with the Houses of Parliament.