Two things to speed up your Vista system:
1. Use ReadyBoost. Plug in a USB memory stick, if the device is adequate to work with ReadyBoost you can configure it. From the Autoplay dialogue select Speed up my system, check Use this device and then decide how much memory you want to use. If your computer is 8 yrs old it may be USB1 so you may not get a great improvement. See Vista Help for more details.
2. Turn off some, or all, of the Vista visual effects. Click Start then right click Computer and choose Properties. Select Advanced System Settings from the LH pane then click the Settings button under Performance. You can now deselect individual effects, or simply select Adjust For Best Performance to turn all the effects off.