Here’s a script that will help you find the disk drive with the most available space.
create proc os_bigdrive @driveletter char(1) out ,@debug tinyint=0
as
create table #diskspace(drive char(1) null , space int null)
if
@debug > 0 exec master..xp_fixeddrives
insert into #diskspace exec
master..xp_fixeddrives
set rowcount 1
select @driveletter = drive
from #diskspace order by space desc
set rowcount 0
go