About Exchange Server 2010 ,,,,, Can't run Test-ServiceHealth Cmdlets

i want to test the Exch 2010 SP1   Services using the cmdlet    Test-ServiceHealth  but i am getting the following error :

[PS] C:\Windows\system32>get-servicehealth
The term 'get-servicehealth' is not recognized as the name of a cmdlet, function, script file, or operable program. Che
ck the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:18
+ get-servicehealth <<<<
    + CategoryInfo          : ObjectNotFound: (get-servicehealth:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

Please Advise ....