Here are a list of daily basis counters to monitor for your Windows network.

Memory:

memory\available bytes
memory\cache bytes
memory\pages/sec
memory\page reads/sec
memory\pool paged bytes
memory\pool nonpaged bytes

Processor:

processor\% processor time(all instances)
system\processor queue length(all instances)
processor\interruptes/sec

Disk:

physical disk\disk reads/sec
physical disk\disk writes/sec
logical disk\% free space
logical disk\% disk time
physical disk\current disk queue length(all instances)
physical disk\split io/sec

Network:

network interface\bytes total/sec