Thank you Jo*Mar. I've read through those suggestions but I'm still no better off.

I've done a full system scan and I've done a separate spyware scan ..... both came back clear.

I've tried to shut down and restart, and still I can't turn it off. So far it's only the laptop that I've tried, as I rarely use the desktop now. That's more of a backup incase I need it.

The new modern is an ADSL (wired) one that allows me to run up to 10 computers off it. I have 2 PC's (a desktop and a laptop), and my daughter was able to connect her's as well while she was here.

I don't know if installing the new modern has caused my problems or not, because I was able to turn off normally for the first few days.

Also, can somebody please tell me if I'm doing any damage to my laptop by holding down the power button and closing down that way? I've done it several times now and I always get an error message when I switch it back on again. Thank you.