I have a Dell laptop that has Vista on it - it became impossible to use and the email wouldn’t open at all no one could sort it -least of all me.
The question is if I reformat is (correct wording?) can I/Should I install Linux as the OS and if which case which one MINT? Can I download this onto a USB from my other laptop? Is all this actually feasable for soemone who has only just grasped the difference between the operating systema and Microsoft word/Excell/powerpoint etc?
Hi Steggles, and welcome to the forum. 
can I/Should I install Linux as the OS and if which case which one MINT?
Yes … I’d suggest Ubuntu or Mint or PeppermintOS as good starting points … Though it may help to know the model of Dell and/or it’s spec to be able to advise better.
Can I download this onto a USB from my other laptop?
To create a Linux LiveUSB on a Windows PC, you’ll need 2 things
a) The LiveCD ISO image of your chosen Linux distribution
and
b) An application that will install that image to a USB stick … such as Universal USB Installer:
http://www.pendrivelinux.com/universal-usb-installer-easy-as-1-2-3/
The middle part of this posting:
http://linuxforums.org.uk/index.php?topic=9782.msg70071#msg70071
should show you haw to download the LiveCD ISO image of your chosen distribution, then use the Universal USB Installer (linked above) to install it to the USB stick.
BE AWARE … Not all PC’s can boot from a USB stick, so burning the ISO to a CD or DVD may be a better idea … though if your system came with Vista preinstalled, it’s probable that it can boot from USB sticks
Is all this actually feasable for soemone who has only just grasped the difference between the operating systema and Microsoft word/Excell/powerpoint etc?
Yes … and you’ll probably find it quite easy (and we’ll help) … You’ll also be able to boot to a fully working Linux desktop from the LiveCD/LiveUSB without making any changes to your hard drive, so you can “test drive” Linux before deciding to install it over (or along side) Windows.
(though it will obviously be slower4 running from a USB stick … so don’t make any speed assumptions from a LiveCD/LiveUSB)
If you have any question, feel free to ask
want to ‘second’ what mark said,if the laptop has the ability to boot off USB [and have already got a USB stick available] ,its always a handy and cheap option in comparison to cdrs/dvdrws-especialy if get a taste for linux and fancy trying out different distros. ;D
the distro to use depends entirely on ones computer confidence and ability to learn,some linux/unix beginners have gone straight to slackware,gentoo and arch or the BSD platform because they learn technical stuff quickly and have a lot of confidence in going straight at the ‘deep end’ in dealing with a totaly alien environment.
other beginners prefer to take things slowly and stick with some familiarity whilst choosing to learn linux at their speed and choice-some good distros for people who feel like this woud of course be ubuntu,but also mandriva and mint [be aware though,mint is bloated due to tailoring itself towards those who want an out of the box experience,so it isnt the fastest for a lesser powered machine,totaly lagged on dads pc which is a few years old but still modern].
pearOS is a good beginner friendly/out of the box distro to [if happen to like the look of mac OSX,which is what it is based on],have got it on a USB stick of mine [well,dads,not mine] and personaly didnt have a bad word to say against it so far.
for beginners who woud like something middleground-neither hardcore nor casual;there is a heck of a lot of choice; just look at http://distrowatch.com/ or http://iso.linuxquestions.org/ for ideas.
there are also quite a few specialist distros,aimed at people who are into particular subjects-these distros arent anything special over others but the software they contain by default is usualy almost completely designed around the subject.
there are even specialist distros based on christianity and islam-forget what their names are though.
if have got any particular interests or requirements [such as the looks/style] ,give us some ideas as we can offer ideas on where to look further as well.
the ‘look’ of a distro is down to both a desktop environment- http://en.wikipedia.org/wiki/Desktop_environment and window manager- http://en.wikipedia.org/wiki/Window_manager ,so its not a problem if a distro doesnt look appealing as the user can use a package manager or manualy download a new desktop environment [such as LXDE, KDE, GNOME, XFCE…] and/ or a window manager [such as fluxbox,open box,rat poison…],and these can be changed at any time at the login screen.
there is another program on the site mark linked to which is like a next step up-YUMI,it woud be well worth a try once have gotten used to USB booting as YUMI partitions itself to allow as many distros as wanted/can fit on the stick,YUMI is the program had used for mine this week.