Can't access my server from this computer

This morning I’ve suddenly started having problems accessing my server – I initially tried to connect from Dreamweaver using ftp to make some small amends to my site, but then when I went back to Chrome and typed in my site address or WP admin address it came up with this:

ERROR
The requested URL could not be retrieved

While trying to retrieve the URL: http://yachtibis.com/

The following error was encountered:

Connection to 82.165.80.107 Failed
The system returned:

(110) Connection timed out
The remote host or network may be down. Please try the request again.

Your cache administrator is webmaster.

The same thing happens with Firefox. The word “webmaster” opens an Outlook email to an obscure email address. It is only happening from this PC; other site users aren’t having the same problem so I presumed it was a malware on my computer but neither McAfee or Malwarebytes have discovered anything…..could it be a virus on my server blocking access from this PC rather than one on my PC blocking access to the server?

Whatever it is hasn’t blocked access to another (non WP) site on the same server, but it has to a couple of other WP sites I host there.

What can I do to get rid of it? My website is http://www.yachtibis.com and seems to open fine on other people’s computers!

Thanks
Sam