Ok so you have vista and you install all the updates but one thing you will notice is that there is a new driver out for your network adapter, you go to install this new update and suddenly everything has gone mental and you keep dropping out constantly.
Your problem is the new driver you need to revert back to the original driver and disable the Updated driver within windows update so vista doesn’t install this again.
You say to yourself “no it isnt” trust me it is, i spent days figuring this out and i thought to myself i will just revert my network driver back and see if that does anything and it did.
Go to Device Manager, the under network adapters right click the adapter and go to properties. Next click the driver tab and click roll back Driver, once done restart and you should now notice that it doesn’t drop out anymore i have tested this and it works 100%.
If the Roll Back Driver box is grayed out you will need to open system restore and roll back your system to the time you installed the driver but i seriously recommend that you back up anything that was installed after you updated the driver other wise your going to have problems running applications :p