When Windows Server 2008 was RTM
back in February 2008, Hyper-V was included in Beta
version. And then we had two release candidates, RC0 and
RC1, till
Hyper-V was RTM on June 26- 2008.
If you already had Hyper-V role
installed , then you can identify the version you are
running by :
Using
the Command Line
Open CMD, and then
type the following line and hit the
Enter key
wmic datafile where
name="c:\\windows\\system32\\vmms.exe" get version

and the result would look like :
If you have the RTM version of
Hyper-V , the version would be 6.0.6001.18016

If you have Release Candidate 1, the
version would be 6.0.6001.18010

If you have
Release Candidate 0, the version would be 6.0.6001.18004

and it would be 6.0.6001.17101 if you have the beta
version of Hyper-V that was included with the RTM
version of Windows Server 2008
Using Hyper-V Manager
Console
The second method is by using the
Hyper-V Manager console. Open Hyper-V Manager Console, click on
Help > About Hyper-V Manager
...

If you have the RTM version of
Hyper-V , the version would be 6.0.6001.18016

If you have Release Candidate 1, the version would be
6.0.6001.18010

If you have
Release Candidate 0, the version would be 6.0.6001.18004

Finally, if you have the Beta
version of Hyper-V that was included with the RTM
version of Windows Server 2008, then the version would
be 6.0.6001.17101
But what if you have installed Windows Server
2008 and intend to install Hyper-V role ( you have not
installed Hyper-V yet ), and you are
wondering which Hyper-V version your Windows Server 2008
has ! Is it the Beta version that was included with
Windows Server 2008 that was RTM back in February-2008, or is it the
RTM version of Hyper-V ( Hyper-V RTM might be slipstreamed with
Windows Server 2008 ) ? To identify the version of
Hyper-V before it is being installed on your machine,
then follow the below steps:
Open Server Manager,
expand the Diagnostic node and then
click on Device Manager

Expand the
System devices node, and select one of
the
Virtual Machine (vmBus) devices, open its Properties,
click on the
Driver tab, and check
the driver version.
If you have the RTM version of
Hyper-V , the version would be 6.0.6001.18016

If you have Release Candidate 1, the version would be
6.0.6001.18010

If you have
Release Candidate 0, the version would be 6.0.6001.18004

and it would be 6.0.6001.17101 if you have the Beta
version of Hyper-V that was included with the RTM
version of Windows Server 2008.
Summary
Either you have
installed the Hyper-V role or not yet, you can identify
which version of Hyper-V your Windows Server 2008 has.
This can be done either by using the command line, the
Hyper-V Manager Console, or by checking the driver
version of one of the vmBus devices.
To summarize the results :
Version |
Hyper-V
Beta |
Hyper-V
RC0 |
Hyper-V RC1 |
Hyper-V RTM |
6.0.6001.17101 |
6.0.6001.18004 |
6.0.6001.18010 |
6.0.6001.18016 |