How do I find out the amount of space left on my server?

In VBScript, you can do this: 
 

<%      set fso = CreateObject("Scripting.FileSystemObject")      for each drive in fso.Drives          cDriveName = fso.GetDriveName(drive)          set cDrive = fso.GetDrive(drive)          if cDrive.DriveType=2 then              response.Write cDriveName & " - " &_              formatnumber(cDrive.FreeSpace/1024/1024,0) &_              " MB free<br>"          end if      next      set fso = nothing  %>

 
In JScript, you can do this: 
 

<script language=jscript runat=server>      var fso = new ActiveXObject("Scripting.FileSystemObject");      for (d = new Enumerator(fso.Drives); !d.atEnd(); d.moveNext())       {          if (d.item().DriveType==2)          {              Response.Write(d.item() + " - ");              var space = d.item().FreeSpace;              space = Math.round(space/1024/1024);              space = space.toLocaleString();              Response.Write(space.substring(0,space.length-3));              Response.Write(" MB free<br>");          }      }       var fso = null;  </script>

 
If you are concerned about the space on your SQL Server machine, you can do this: 
 

EXEC master..xp_fixedDrives

 
Which will return a list like this: 
 

drive MB free   ----- -----------   C     2435  D     7596  E     6097  F     7892  G     7393

 
Note that this is an undocumented extended stored procedure, and should not be used in production code (since its behavior may change in future versions). Another alternative, for a single drive, is to parse the results of the following statement: 
 

EXEC master..xp_cmdshell 'dir c:\'