Security software vendor PC Tools released research today that suggests Windows Vista is not as immune from online threats as Microsoft had once suggested.

Since Vista's release last year, Microsoft has hailed the operating system's security features. Some have even claimed the operating systems would make anti-virus software obsolete.

PC Tools took that opportunity to examine Microsoft’s claims, and conducted research over six months with 1.4 million of its customers using its ThreatFire Anti-Virus Software.

If a threat occurred on the machines, it was sent to a back-end service of PC Tools, which was then ran through a third party anti-virus company to check the validity of the threat.

The research found that while Vista had improved upon XP’s ratio of 1,021 per 1,000 machines, there were still 639 threats per 1,000 machines running Vista.

Strangely enough, some of Vista’s biggest security problems may actually stem from features that were supposed to increase security.

“Macs and Vista have similar security prompts that pop up when you install software,” said PC Tools CEO Simon Clausen.

“On Macs, those prompts come up a lot less often, usually for really big procedures, but on Vista, they come up a lot more frequently.”

“I think after a while, Vista users just get tired and become blasé about their security, and either ignore the prompts or turn them off- people don’t want to have to be a security guard for their PC.”

Clausen stressed that although Vista boasted somewhat of a security improvement over XP, there were less threats to Vista as it has a smaller distribution base.