error after installing service pack

Hi,

I have got this computer and have just re-installed windows xp home edition using the 'acer recovery cds'. It went fine and installed fine. After installing, the first thing I did was open up windows update and start installing the windows xp updates. After ages of download heaps of different updates, restarting a couple of times as instructed, service pack 2 was installed. After installing, which went fine, i restarted as instructed, and after restarting the 'welcome to service pack 2' message came up for about 5 seconds and then the computer just randomly restarted. Then, started running the scandisk and came up with lots of messages like "xxxxx is cross-linked on allocation unit" and "first allocation unit is not valid - entry will be truncated" these messages came up heaps and after a few miniutes windows started up normally. But, then as soon as I clicked my username to log in, the computer randomly crashed again and the scan disk came up with the same(or similar) thing.


SO, I put the install disks in again and reformated again, as i couldn't be bothered going through the process of figuring out what the problem is. BUT, then it happened again.

I'm at a loss as to what to do. It can't be a virus as i've just formated! And it only happens after installing service pack 2.

Thanks!

Another thing I forgot to mention, my internet lan connection is as follows"

I have a wireless router connected to a cable modem which gives the internet. I have a 'wireless ap client' which is connected to my computer which has the problem.. Hope its not confusing, but i'm wondering if the issue could be some sort of corruption with the download of the service pack??

Just managed to successfully start in safe mode