New hard disk slows network speed...?

[burns flipper]

I think it's a Seagate 500GB SATA. The drive itself works fine, it's just the network speed when it's in.

How do I ground it? It's screwed into the case in a 3.5" bay, so are you saying I need to jam a paperclip somewhere special between the HDD and the part of the case it's screwed into? So, the metal top part of the HDD case and the metal of the 3.5" bay?

[Harrison]

The metal drive bay might not actually be grounded fully with the superstructure of the case. I would connect a wire from the metal casing of the HDD to somewhere on the chassis of the case, preferably part of the main structure, and see if that helps. It might not, but its worth a try to rule it out.

Have you also tried swapping the SATA cable being used? These can suddenly being faulty and cause strange behaviour.

It could also be an issue with the IDE to SATA converter you are using. I've had issues with these myself, either not working or losing drives during use... especially the USB to IDE/SATA adapters. Had a nightmare with one of those.