I use parallels desktop 8 on MacOsX 10.8.2, my virtual machine is WindowsXP sp3 (bootcamp) When I start windows from bootcamp (no virtualization), the serial number of the Hard driver is 6WR2HY8K. When I start windows from parallels, the serial number of the Hard driver is 5BDJQ4GP4H5M7015MXEG. Autocad Iventor require new activation, Windows Xp require new activation. Have you a solution for change the serial number of the virtual driver (5BDJQ4GP4H5M7015MXEG). I read the driver serial number with DiskId32.exe (freewere from internet). This is the example in Parallels. **** DISK_GEOMETRY_EX for drive 0 **** Disk is fixed DiskSize = 500107862016 Trying to read the drive IDs using Smart Drive 0 - Primary Controller - - Master drive Drive Model Number________________: [ST9500423AS (disk0)] Drive Serial Number_______________: [5BDJQ4GP4H5M7015MXEG] Drive Controller Revision Number__: [F.0K371W] Controller Buffer Size on Drive___: 2097152 bytes Drive Type________________________: Fixed Drive Size________________________: 500107862016 bytes Hard Drive Serial Number__________: 5BDJQ4GP4H5M7015MXEG Hard Drive Model Number___________: ST9500423AS (disk0) Computer ID_______________________: 641520608 MAC Address: 08-00-27-00-48-E4