The recently launched Window Vista may not be as secure as users have been led to expect. Several security experts have raised their concerns about this issue. Webroot Software, one of the plethora of security companies that helps protect Windows users from attacks, said that buyers should be aware of the potential holes in Vista. In testing, the company highlighted that the new Windows Defender program failed to block 84% of viruses – including 15 of the most common pieces of malicious code. Although being lauded as the most significant advance from Microsoft in this generation, Vista has been repeatedly criticized. A number of campaigners have criticized the heavy technological burden the new system will bring. In order to utilize Vista’s capabilities fully, many will need to buy expensive add-ons, or buy an entirely new system.