update: There was an auto restart this morning and I dint see any errors after that successful auto restart

But a couple of weeks back I had my SAN Admin carve out a LUN for 40GB from Raid 1 group and moved tempdb to that T:\ drive. The move went well and I restarted services after that. And right now I see the T:\ Drive at 8.0GB.

This morning there was a sql service auto restart because of contention/issues in tempdb and when I query

SELECT name, physical_name FROM sys.master_files WHERE database_id = 2

I see the below result and the space on c:\ drive went down by 8.0GB

name physical_name

tempdevC:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\tempdb.mdf

templogC:\Program Files\Microsoft SQL Server\MSSQL10.MSSQLSERVER\MSSQL\DATA\templog.ldf

Can some one please tell me why did that move back to c:\ drive?? and is there a way to fix this permanently.

Thanks a bunch