|In addition to the above advice, did you install all the drivers for your motherboard? Especially the chip set drivers? |
One other point to note. Not all 20GB hard drives are created equal. Yours may be a slower model. As mentioned above, 1GB is not enough so you are constantly using the swap file on the drive. That is always slower than RAM but with a slower drive, or a drive running in PIO mode, it will be even worse.