Go online as in...? Connect to the internet? Or it's appearing as "Offline" on your computer when you try to print?
Is your computer also connected through the HT2000w, or is there a router between the computer and HT2000w? You may need to set the printer on the computer up again (rerun the installation software) since it is now on a different network than before.
1: Is the computer directly attached to the HT2000w? Yes/No
2: The printer is connected to the HT2000w Wifi? Yes/No
3: What Operating System is the computer using? Win10, Win8.1, Win7, or an Apple OS?
Yeah, I highly suggest downloading the latest drivers from HP, and do a reinstall. Unless @BirdDog or @Gwalk900 know how to change the printer properties in Win8 to match the IP address of your printer on the new wifi network. I also suggest reading over the users guide to see if it has any information about connecting your computer back to it.
Make sure you remove your printer from Devices and Printers before trying to do a reinstall.
On my Brother printer I can look at the WiFi settings on the printer screen and see the address assigned, then go to Printers and Devices in Windows and force a connection by adding it. Have had to do that several times over the years.
Same problem with my HP Officejet Pro 8625 (wireless connection) but mine started with the installation of my new Netgear R6400 wifi router. It wasn't immediate tho. Then it went off-line again after the Gen 5 update. Run the HP Print and Scan Dr and download the lastest software from HP.