If you go for Windows then you will only be able to buy the latest Window 8.1 Update version as Windows 7 is no longer available. However the good news is it has improved a great deal since the original WIndows 8 release last year. The next version is already available for beta-testing and will be called Windows 10 ( not W9).
An Apple machine is certainly worth thinking about if you can afford it. There is no doubt it comes with a price premium but many think it is worth it for the good after sales service. Despite being based on the same hardware as PCs they hold their value well which sweetens the pill a little.
Might be worth getting someone to look at your pc to see if anything is running in the background and slowing it up, and get it removed.
Kef - go for windows 7. You CAN still get it if you know where to look as I just brought it on my (aka I brought and paid for) work laptop. I'll get you the details tomorrow as I'm tucked up with my hot water bottle right now!
I'm using Win 7 with my Dell Inspiron desktop and wouldn't want to upgrade just now, particularly to Win 8.
When I do need a replacement, I would have a new tower built for me by a local firm, reinstalling Win 7 with my disc, for which I hold the licence.
I'm lucky to have a 50+ Mb broadband.
Windows 7 is about to lose support.
Windows 8 is hateful.
I just went all Apple, have iphone, ipad, macbook and imac!
I think they are ALL appallingly non user friendly ..... or is that just ME?
Apples may be more expensive but they last longer??