Drivers Missing After Startup

Hi i just put together a cheap pc for my son, he's 5 so nowt fancy, it's a INTEL® Pentium® 4 E2160 Dual Core CPU, MSI PT890 Neo mainboard
, 400W iCute ATX Power Supply, nvidia geforce 7200 128mb and 1gig of ram 2x512 modules, 2 x hard discs 1 40gig and another 20 gigs, 2x dvd drives and a internal memory card reader. It's running Vista Home Premium.

Problem is that after the computer is shut down some drivers are lost and on next powerup vista installs them again, some of the drivers are, sound, pci-bridge or summit? the internal usb reader (this was added after this problem), it's just annoying, if i leave my external hard drive plugged in to my desktop or laptop it doesn't reinstal the driver next startup, so why does it do this with parts? built into my sons pc? Also i got him a wireless keyboard and mouse bundle at staples for £15 - Labtec® Ultra-Flat Wireless Desktop, the mouse nearly always stops responding at some point when you left or right click, you can move the cursor around the screen but cant close apps etc, and if you hover over objectdock, you can tell that something is slowing it down as it should pop out at you quick and smooth when you hover the cursor over it? is it the mouse etc or is it related to the first problem???:4-dontkno
Any help would be much appreciated
Thanks:smile: