Windows 7: Unable To Connect To Network Devices

Hi,
I’m sure this will be a simple solution, but I have spent 2 days sitting in front of my PC trying to figure this out with no luck. I run one PC, One Laptop, 2 TV’s, and iPhone and iPad off the wireless modem/router (Thomson TG782T) I connect my ADSL through. All was working fine wirelessly until my PC required reformatting. Although I am able to connect to the internet on the PC, the PC is now unable to detect my network HD (Western Digital NetworkHD connected via Cat5 to the Router) or printer (HP Officejet Pro 8500 Wireless connected wirelessly). When I access the router homepage via the PC is shows me that the router is connected to the Ethernet HD and wireless printer. Is there some way for me to once again access these devices.

Also at the same time (and possibly connected) I have been unable to detect the active HOMEGROUP that I have running on the Laptop via the PC, and as a result I am unable to connect to it either. I have tried creating a HOMEGROUP on the PC and searching for it on the laptop, but this group is unable to be detected. The laptop is still able to connect to the network HD and print via the wireless printer. I have synched the time on the PC and Laptop by utilising the Internet Time Server: time-nw.nist.gov on both devices.

Any recommendations?