My laptop is running so S L O W L Y - what can it be?

[Gameboy]

Have been having problems when trying to log on in the morning - it kind of whirrs and clicks (like it is shuffling data around) for ages, and often gets stuck/ crashes.

So far ...

• I have defragged

• I have run SPyBots and deleted all my temporary internet files etc

• I have turned off automatic downloads from Windows, and 'Restored' it to a previous date, which seems to be working at the moment, but only worked for a couple of days last time.

The memory is only half full, and I am not runnning huge programmes/ files when this happens.

Am running Windows XP, and my first thought is that one of the automatic downloads has screwed it up somehow??

Any ideas? Similar experiences?

are you on a wireless network? is someone using your connection?
no idea if that would slow it down or not
mine was quite slow last night and I closed it all down, unplugged the connection and started it up all again - did make a difference

Have you got Norton or any similar anti virus programme? I recently had a new laptop and it had a free trial of norton, it was soooo slow until I uninstalled it.