How to configure your ESET product as follows (assuming you installed the definitions into C:\Update)

* For ESET NOD 32 3.x/4.x

- Go to Control Center, Update modules, NOD 32 Update
- Click Servers, add C:\Update as new server and click accept/ok
- Close all opened windows and Update ESET NOD 32 from tray icon

* For ESET Smart Security 3.x/4.x

- Toggle to display Advanced mode
- Go to Setup, choose Advanced setup
- Go to Update, right to the field 'Update server', click Edit
- Under Update servers, add C:\Update as new server, click Add and OK
- Close all opened windows and Update ESET Smart Security from tray icon