Explorer freezing/not responding/lagging

When I right click on START, choose explorer, the window pops up, but suffers from the following:

Freezes, so I click close, it tells me it is not responding, so I click cancel and then I can get into explorer as normal. As say ‘normal’ but is is still slow, until I get into Programs – then it beahves normally.

i have XP SP 2, AVG, Adaware, Spybot, hijack this, ran all. Defragged etc. ran scan disk. But still no change.

In todays age I cannot afford to wait for 15 seconds to get into explorer – you know what I mean!! Any help would be gratefully appreciated. One other thing I did tinker with the Services under admin. I (as far as I am aware) restored all the services that i disabled. Please help….Mark