On the 64-bit Windows Vista version of Microsoft, all kernel-mode applications such as device drivers are required to be digitaly signed. This will somehow lessen the malwares that run under kernel-mode and also rootkits.
But a digitally signed application doesn’t make itself bug-free. Though you can pin-point who will be responsible for the said program. Microsoft is requiring developers to obtain Publisher Identity Certificate (PIC). PIC is based on VeriSign Class 3 Commercial Software Publisher Certificate. The certificate must be embedded on the binary.Thanks to eWeek: