Laptop boot up problem

[DaisyMae]

I have a six month old hp laptop with Vista and I have a minor but quite irritating problem on boot-up. I get the 'Welcome' page and then instead of the desktop I get just a plain white screen for about three minutes, then I get the desktop. Everything else is as normal and I have not problems during use, only on boot-up. Can any one give me any ideas on how to eliminate this problem or even what may be the cause.

Thank you.

[ACtheTROLL]

new fault?

what have you done recently ?

[DaisyMae]

Thank you for replying - yes, I suppose you could say this is a new fault, about three weeks or so old, all I have done is downloaded the patches and updates, I think I first noticed it after downloading Service Pack 1 (I think). Other than that, only emails and a few pictures of family in them. I use my laptop for correspondence, eBay (seller) and web searches and shopping (only known and well used sites). I would appreciate your help.