BOSTON – Sixty-five percent of businesses surveyed by Forrester Research said they plan to buy software that will protect their systems from spyware.

The survey was done with Technology decision makers at 185 North American companies. While 69 percent of large enterprises said they would purchase anti-spyware tools this year, only 53 percent of small and medium businesses said they’d buy such protection.

The study exposed several cracks these companies? anti-spyware strategy. Almost 40 percent of respondents didn?t know how many machines have been infected. About 17 percent said their systems had already suffered from spyware, a number Forrester predicts will climb to 25 percent within 12 months.

The survey also showed that although 80 percent of the companies already have anti-spyware tools, they were “introduced in an ad-hoc manner over the past two years to fix infected PCs,” Forrester said.

Only a very few firms had any idea how many support calls are related to the spyware invasion. The 44 percent of respondents able to guess estimated it to be 7 percent. PC maker Dell, on the other hand, blamed 20 percent of support calls from its customers on spyware.

The most popular anti-spyware software tools are McAfee and LavaSoft’s Ad-Aware, with 42 percent and 36 percent respondents using them respectively.