Been there man, it sucks. Here's some tweaks to get your group back up and running:
Disable system file startup scans. You can only turn them off through ERA. Disable email file startup scans thru ERA. Disable email client and email scanning thru ERA.
After a fresh client install the machine will have some lag processing all of the definition updates. Should subside after the third restart. Also, ESET's repository has a horrible slow pipe, we ended up creating an internal update mirror to bypass every client dialing back to ESET's repository.
Good luck!