Here is a script I use to look at available drive space where database files are located:
sp_helpdb databasename --< Name of DB here
/* This runs on SQL 2008 R2 SP1 & higher ONLY */
DECLARE @dbID INT = 2 --< Database ID - TempDB = 2
DECLARE @fileID INT = 2 --< File ID from sp_helpDB above
select database_id, file_id, volume_mount_point AS 'Drive', logical_volume_name,
(total_bytes/1024)/1024 AS [Drive Size MB], (available_bytes/1024)/1024 as [Free MB],
100-(100*(CAST(available_bytes AS DECIMAL(38,2))/CAST(total_bytes AS DECIMAL(38,2)))) as 'Percent Full'
from sys.dm_os_volume_stats (@dbID, @fileID)
I do have admin access to the OS's so I use this mostly because it is faster than logging in via RDP, and because there is less risk of accidently clicking the wrong thing when on production servers.
This is also an IT management issue. If you are reponsible to make the databases run optimumly, you need either desktop access to the server OS, OR an OS Administrator must be assigned to work closely with you. Otherwise you're working in a Dilbertian environment.