busylizzie

Windows has just stopped working on my laptop (Dell inspiron 1525), how can I fix it? (NB I am using a different comp to ask this question). My laptop, although not very old, has been dodgey for a while, occasionally just shutting itself down unexpectedly and deciding not to be able to find the internet after we moved to Virgin, causing me to have to use a dongle but a few days ago Windows just stopped working. I can't access the internet at all now, even with the dongle and the default right hand side bar on the desktop has stopped showing. It claims 'Windows is not available' but I can still access all my documents and other programs. I have been using a make-shift virus protection program (ESET SmartSecurity 3.0.645.0) that a friend installed after my Norton AntiVirus expired, which now claims that it cannot be updated because it's not compatible or something, so I suspect the problem could well have been caused by a virus... Is there any way I can reinstall Windows and some virus protection so that it will work again or do I have to wipe my laptop??