See the end of thread;
http://forums.parallels.com/thread12874-2.html
I belive this may be relevant. I use one copy of XP and switch seamlessly betweent BC and VM. The trick is changing the "realtek" VM interface driver to match the real "en0" MAC address.
Also; Taken from VMware Forum is seems memory thresholds can trigger it reactivation request too. I give XP 1024mb in VM.
Known Issues
Product Activation
The Microsoft Windows XP product activation feature creates a numerical key based on the virtual hardware in the virtual machine where it is installed. Changes in the configuration of the virtual machine might require you to reactivate the operating system. There are some steps you can take to minimize the number of significant changes.
Set the final memory size for your virtual machine before you activate Windows XP. When you cross certain thresholds—approximately 32MB, 64MB, 128MB, 256MB, 512MB and 1GB—the product activation feature sees the changes as significant.
Note The size reported to the Windows product activation feature is slightly less than the actual amount configured for the virtual machine. For example, 128MB is interpreted as falling in the 64MB–127MB range.
Install VMware Tools before you activate Windows XP. When the SVGA driver in the VMware Tools package is installed, it activates features in the virtual graphics adapter that make it appear to Windows XP as a new graphics adapter.
Tim
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Last edited: Jun 24, 2007