XP Pro logon to domain

I have just purchased a new Compaq Evo 1020V running
windows XP Pro with XP Office Pro.
When I start up the machine on local machine settings
there is no problem.
When I start up the machine to log on to our corporate
domain (SBS2000 Server+SQL server) it takes ages to boot
up - 5/6 minutes.
The machine replaced a W2k Pro laptop which, apart from
the screen packing up, gave me no problems.
All the network settings appear OK but obviously
something is wrong.
During use, it also seems to have regular problems
hanging programs and it seems that there may be
difficulty in negotiating the network connection.
Anyone have any thoughts on this matter? (apart from
switching back to the tried and tested W2k)?