So is the best o/s windows 7 professional and what about explorer please, sorry Varche to ask on your post, but this seems to explain some issues i am having Thanks 
Without a touch enabled device, Windows 8 looks clunky. Sadly, it appears that Win 8.1, formally Blue, won't fair much better

So Windows 7 would be my preferred choice of OS now. Hence virtually every PC (I have a few!) in the house runs it.
Given the cost difference between Win7 Home Premium and Win7 Pro, unless you need Pro (ie, bitlocker and proper domain integration - not needed by many home users), Home Premium makes more sense.
If the machine currently runs Vista, I probably wouldn't upgrade it unless I needed to. And to be honest, if it does, its likely to be 4 - 6 years old, so not really worth spending money on, when its about ready for the scrapheap.
If the machine currently runs XP, you need to consider moving away, as extended support ends in a few months (so no more security patches, which means, realistically, you are playing Russian Roulette plugging it into an Internet enabled network). Its pretty likely that a machine built in the XP era is going to need a hardware upgrade, as well as the licence to run Windows 7, so may not be viable.
For most people, anything that is Intel Core2 Duo or higher (ie, Core2 Duo/Quad, i3, i5, i7) and has 2Gb RAM should run Windows 7 well enough. Laptops may need to have the hard disk changed to an SSD to bump the speed up enough to be usable. Netbook owners have little choice to run Win7 - max out the RAM (2Gb for most Atoms) and SSD it, you'll still find it sluggish in the first couple of minutes of switching on.
As for browsers, thats personal choice. The only one of the big 3 I would passionately say avoid is Chrome, on security grounds.
Personally, I tend to use IE, as its updates are integrated into Windows Update, so its one less thing to remember to update. Firefox has some nice tools for web developers, but needs constant updating, at least weekly.
I find IE faster and stable than the others. Its reputation of instability comes from the fact it allows plugins (eg, Java, Flash, Acrobat, toolbars, search etc etc), and some of these are dire. The poor Firefox and Chrome people are just beginning to realise this. With all browsers, be picky about the add-ons you allow. I honestly can't remember the last time I had IE crash, and I tend to use it all day, every day.