By default VMWare uses E1000 — An emulated version of the Intel 82545EM Gigabit Ethernet NIC and the vmware tools nor XP include the drivers for this emulated NIC.
Solution 1
Download the drivers from Intel and install
Note: for PXE boot scenario solution 1 is the only answer as synthetic adapter does not support PXE.
Solution 2
Change the emulated NIC to the one that the vmware tools has drivers to
Edit the VMX file of the VM, set the following property
ethernet0.virtualDev = "vmxnet"
References
http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&externalId=1003020
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1001805
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009104