In general one installs the motherboard drivers after installing an operating system.

Perhaps they were included in the Acer Recovery.

Wouldn't hurt to run them from the disk but if everything is working Okay just leave it be.

I really don't know about the Acer setup. Anytime you alter partitions you risk data corruption.

Perhaps that Acer partition was susceptible to corruption if altered.

Contacting Acer might help. http://global.acer.com/support/index.htm