My test machine is a Dell PowerEdge 2900. I was able to install and access OpenManage on Hyper-V Server 2008 R2 as follows:

1. Download the latest Dell Systems Management Tools and Documentation DVD. I found version 6.1.0 A00 here. Note that this is actually two downloads that must be concatenated before burning the DVD–see the Installation Instructions on the download page.

2. Follow Dell’s article, “Installing Dell OpenManage Software On Microsoft Windows Server 2008 Core and Microsoft Hyper-V Server.” Only install the Managed System Software, not the Management Station Software.

First run the prerequisite checker by running these commands at the command prompt (assuming the DVD is in drive E):

E:
cd \SYSMGMT\srvadmin\windows\prereqchecker
runprereqchecks.exe /s

Update 10/12/2010:  Path corrected–thanks to comment from Ian N.

The instructions for the prerequisite checker tell you to take certain actions depending on the return code. Use this command to view the return code:

echo Return Code = %ERRORLEVEL%

My Return Code was -2, which, according to this article, means “The operating system is not supported. The Prerequisite Checker will not run.” My hunch is that this is because the software has not been updated to recognize the R2 version of Server 2008. I went ahead and ran the installer anyway:

cd \SYSMGMT\srvadmin\windows\SystemsManagement
msiexec /i SysMgmt.msi

After agreeing to continue without having run the prerequisite checker, the installation completed successfully.

3. Open the firewall for the OpenManage web interface default port 1311:

netsh advfirewall firewall add rule name="Dell OpenManage Server Administrator Web GUI" dir=in action=allow protocol=TCP localport=1311

Note Knowledgebase article 947709 is helpful on the netsh commands. However, do not just cut and paste its examples:  as of this writing, the quotation marks are all formatted as closing quotation marks (”), so the commands will fail. Replace those quotation marks with standard “vertical” quotation marks (“).

4. From another computer, open a browser and type in the following URL (be sure to get the “s” on the https):

https://[computer name or IP address]:1311

After adding the required security exception in your browser (due to the self-signed web server certificate), you should now see the familiar Server Administrator web interface:

There are other advantages to using the full version of Windows Server 2008 R2 as the host OS, but Dell OpenManage is available even from the free Hyper-V Server 2008 R2.