Check Whether drive exists and find the capacity

hi ,

i wrote script check d drive exists , if exist should give size of d drive  here script :-

$check = "d:\" $testobj=get-wmiobject win32_volume -filter  "driveletter= 'd:'" 
$caption= $testobj.caption
if($check -match $caption )     {          write-output " true"         $cap= $testobj.capacity         $capsize= $([math]::round($($cap/1gb), 2))    
write-output " capacity $capsize"     }
else
{       write-output "$check doesnt exist"       }

 i error :-

bad argument operator '-match': parsing "d:\" - illegal \ @ end of pattern.
.
at line:7 char:18
+ if ($check -match <<<<  $caption )
    + categoryinfo          : invalidoperation: (:) [], runtimeexception
    + fullyqualifiederrorid : badoperatorargument
 

i tried -like string worked on local machine , not working on windows server 2008 r2. please help.

if($check -match [regex]::escape($caption) )

Windows Server  >  Windows PowerShell