Just today the internet seems to be going incredibly slowly on my desktop PC (connected to modem via a NetCom powerline adaptor which has worked fine for the last few months).

It is working fine on my netbook (connected by wifi).  Web pages load at normal speeds and when I go into the modem interface via the netbook I can see the connection is all good.

It is just that trying to load any webpage on my desktop PC takes an age - not even as fast as dialup.

So, at this point then I'm pretty sure it has nothing to do with my actual broadband connection (since the netbook connection is working fine). Rather something to do with either my PC itself or my Powerline Adaptor.

My PC can find the network and says it is connected, but cannot connect to the modem interface.
Skype is claiming it is connected too,but cannot place any calls.

I have run a virus scan on my PC.  Nothing came up. I have checked and have nothing in the background either that might slow the connection down. All the lights on the modem and the powerline adaptor suggest the connection is fine.  I have restarted my computer. Still the same.
But that is as far as my noobiness can take me and I am out of ideas.

Suggestions?

ETA: my modem is THOMSON TG585v7


ETA:    FFS. Well waddya know,  I restarted my computer one more time and now, depsite doing nothing different, everything is working just fine.