The electronics of the computer will actually like the cold, although the mechanicals (HDD, opptical drive, fans) will not.
1) Did you load the Via 4-in-1 drivers immediately after you installed Windoze?
2) Did you load latest versions of all the drivers, or just the ones that came on the supplied CD?
3) You don't need 256MB for graphics memory, but with 1GB of RAM that should be OK.
4) Disable any/all unused devices in the BIOS.
5) Disable any unnecessary/unneeded services in the Computer Management Console
Don't expect miracles. It's only a 1ghz CPU.