not a problem

in the batch file call
svrmgrl @your sql file path

in the sqlfile

connect internal oracle
shutdown immediate

you can schedule (at) this batch file from nt.
there is also a shutdown.exe available in windows that shutsdown the computer and restarts it, that we use to get rid of temp files and memory leaks along with our normal weekly database shutdowns for coldbackups. and all this is scheduled.
batch file is like

svrmgrl @sql for shutdown and copying all files using os
shutdown and restart the computer

oracle starts up again when system re starts.