oh.... DL380 G4 is not technically supported to run Windows 2008 R2. You can see here, that you can not select this version of the OS... you can installed non-R2 Windows 2008:
http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?prodNameId=3288132&lang=en&cc=us&taskId=135&prodClassId=-1&prodTypeId=15351&prodSeriesId=397634You need a G5 or later to run Windows 2008 R2.