Long Ping times eg 135ms Cause?

[#1]

Hi,
I am posting on behalf of my sister who is on Plusnet as well. She is having probelms with anything Internet on her PC.
Launching IE and waiting for www.bbc.co.uk as home page can take well over a minute or 2. She is using the standard Plusnet reouter that came with the basic package when she joined.
Using a few speed test (speedtest.net) sites, she gets reasonable dl speeds eg 10Mbps (Plusnet say it is 14Mbps), upload 300Mbps  and a ping of 135ms - the u/l and ping doesn't seem quite right, especially *if* it is ADSL2 (same exchange as me and mine is)
What would be the most likely causes that I should check first, any ideas?
Thanks in anticipation,
Graham.

[#2]

Something nasty on her PC stealing all her upload bandwidth.  If something uses all your upload then you will have real problems with downloading stuff as part of the process needs your end to respond that it received a packet or the other end will assume you didn't get it and send it again. etc...
So eliminate that thoroughly and you can move on to networking issues then.  Probably the easiest to do this is to try using her connection from a device which is known to work well on another connection while hers is turned off.

[#3]

Hi Graham,
Is that a something that is happening on a permanent basis or just at certain times?