The computer has connected to the router, but not to the internet. try to connect the computer directly to the router with a LAN cable for a test. Or you can connect another computer to PA251. The...

You can look for http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=13&PFid=5&Level=5&Conn=4&DownTypeID=3&GetDown=false

Hold on the button for 3-8 secs on the first one. Hold the button for 3-8 secs on the second one.

Does it means all the lights are not coming on? If so, it should be faulty.

It seems that these two options are for storage device like hard drive and printer.

Is the print server connected to a printer or USB HD?