Firstly I have posted this in a number of places and so far havent had advice that I could follow without losing my files, so please bear that in mind.

I have had some strange things happening latley when I use internet explorer, my home page gets changed to a site that just shows advertising, (I keep setting it to http://www.bbc.co.uk but it wont stay that way). On top of that my PC (not the fastest at the best of times) is slowing to a crawl when I start it on, and sometimes doesnt even turn off. I have tried to use my installed norton anti virus, (which is up to date) to scan my computer but it doesnt seem to work. I have also tried to use one from Trend Micro that is online (http://www.housecall.trendmicro.com) and that doesnt work either.

A Colleague told me that I may have a virus or a back door installed and said I should check what ports I have open.... Atfter some confusion I have checked at http://www.ictsc.com/portscanner.htm and it has told me that I have ports 25, 666, 1976 and 8080 open. for details see: http://www.ictsc.com/IP_Port25.htm, http://www.ictsc.com/IP_Port666.htm, http://www.ictsc.com/IP_Port1976.htm and http://www.ictsc.com/IP_Port8080.htm. I followed some of the links on the bottom of those pages but they were of no use. Im not sure what to do with this information.

So, I think I have a virus or a back door, and I need to know how to get rid of it, I have lots of work stuff, photographs and some music stored on my computer and no easy way of taking them off, so deleting it and starting again isnt really an option. Also I need my computer for work, I do my banking and pay bills online, so I think I need to do something about this quick.

Does anyone have any advice? I spoke to pcworld (http:/www.pcworld.co.uk) but they just seem to want me to buy a diferent antivirus or to send my computer in to them, and if it infected they say they have to delete all my programs and files and make a clean windows program.

Can anyone Help?