In Windows Vista, you can speed up the boot time by requiring the processor to boot using 2 processor. This is provided you are using Dual Core or Core 2 CPU.
To change the setting, type msconfig under the start search panel.
Once you have launched msconfig.exe, select <Boot> tab
Click <Advanced options…>
In the panel, top left corner, it shows number of CPU with a 1 in the list box. Change it to 2.
You need to restart the PC.