How to reinstall Vista

[#1]

I remembered that on my shelf I have a full version of W7 which I pre-ordered last year (I think it was about £45).
I activated the key on my Dell but had problems and subsequently reinstalled its own OS which was Vista Business.  It was only in use for about a week or so at the end of last year. I am wondering if I could have put that on. 
The problems are that I haven't been able to run the upgrade adviser, it has been activated though not used for 8 months and it would have been a little more expensive for my friend who is an OAP and struggling somewhat as she is supporting her out of work grandson. 
I must say that reading all your comments confirms that it is very confusing and requires a lot of patience to get things working properly. I should have liked to do the reformat myself but I think that I must leave it to the shop owner as it will be cheaper in the long run and less problematic for me especially regarding drivers.
It just goes to show the importance of making a full DVD backup when the computer is brand new and before using it.  I was going to do this when I get the computer back but not sure  how as it Vista Basic which only has the backup of files but no system files as far as I can see. 
Thank you for the interesting comments.

[#2]

A full version of Windows is transferable; it doesn't matter if you used it previously on another computer so long as you are not still using it.
Windows 7 would almost certainly run on a computer that previously ran Vista, possibly better.  Usually Windows Update will find the drivers you need.  My impression of your account of the agreement you reached with the shop owner is that he is expecting you will find and install the necessary drivers for Vista.  That is the time-consuming and troublesome bit.

[#3]

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Windows 7 would almost certainly run on a computer that previously ran Vista,

That is interesting because I have an MSI laptop running Vista.  As I have the W7 disk I thought that I would run the upgrade adviser on it to see if it would be worth installing on that rather than just have it sitting on the shelf.
The result was that  my CPU is 810MHz and it recommended 1GHz.  Everything else was fine (I added 1GB RAM a couple of months ago).  That is why I haven't installed it. Also, it is running very nicely with Vista HB and dual-booting with Ubuntu 10.04.
The man in the shop will install the drivers and I will get the laptop back with a fully functional and updated machine so I won't have much to 'play' with . 

[#4]

I see Windows 7 as a souped-up version of Vista.  Okay, 7 has some new features but I think Vista & 7 are fairly similar if you look under the bonnet.  If your MSI laptop is working well with Vista and doesn't need souping up, then I wouldn't bother with Windows 7.  If you want to sell me your spare copy I will happy pay you a good premium over the £45 you bought it for.  The retail Home Premium version currently costs over £90! 
I'm glad your deal includes driver installation.  That is the effort-intensive part of the re-install.

[#5]

Quote from: ReedRichards

I see Windows 7 as a souped-up version of Vista.

Yes, it's sort of the upgrade-to-viability Service Pack. Don't be surprised if future Vista SP's make it more "7-like", at least visibly.

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If you want to sell me your spare copy

Highly unlikely to be "spare" in any sense that's "legal". It will almost certainly be an OEM copy licensed to the original hardware and even then only as an alternative install (effectively an upgrade) to the Vista currently in use.
In fact I think the MS licenses don't even allow you to make a dual-boot system in such circumstances, though I'm not sure how the license keys work and if that would be detectable.

[#6]

Quote

It will almost certainly be an OEM copy licensed to the original hardware

No HP - it isn't OEM. As I said in my previous post it is the full version with two disks - 32-bit and 64-bit which I pre-ordered from PC World specifically to put on my Dell laptop.  After a week or so the laptop would not boot up.  I never found out why as the reinstall seemed to go OK but it might have been my inexperience. As it was under warranty Dell asked me to reinstall the original OS which is what I did (with a bit of hassle) and it is now working perfectly. Have sold it to a friend who was in need of a better laptop.
I bought a Sony with W7 in November last year and that is also one of the reasons why I haven't used the disk on my MSI (it is only a spare anyway, albeit a very nice one).
I did think of using it to reinstall 7 on the Sony because it came with a load of bloatware.  However, aside from a few things that I cannot be certain of, I have managed to uninstall most of it. Also, from the Sony forum I have the instructions to reinstall with my own restore disks, less the extras, although I don't know whether I could manage that.  Anyway, no need at the mo because it is 'sound as a pound' as we say in Yorkshire.
Will have a think about the disk RR and thank you for the offer.

[#7]

Quote from: poppy

No HP - it isn't OEM. As I said in my previous post it is the full version with two disks - 32-bit and 64-bit which I pre-ordered from PC World specifically to put on my Dell laptop.

Yes, HP, remember in August last year a Microsoft special offer allowed you to pre-order Windows 7 at discounted prices via a limited number of retailers.  The £45 Poppy paid was a fairly typical price, but the supply sold out very quickly.  What was on sale was the full retail version.  I bought two copies but I used one on my own computer and the other on a client's computer.  I bought a third copy recently for another client for around £87 but the Home Premium version is currently selling for around £93 and I could do with one in stock. 

[#8]

Quote from: poppy

No HP - it isn't OEM.

Apologies, I misread the earlier posts. 
Yes RR I got a copy of W7 Home Premium that way for about £45. 

[#9]

poppy one last thing!!!!!!!!!!!!!!!
my pc came with  OEM vista
its installed on drive C: which is normal
as the pc manufacturer on selling the pc installs the operating system
on drive C:  
then  through a disk partition  on the main hard drive in the computer
he creates a partition , the  usual name for this second partition on the same drive     is  D:\
my vista OEM restore is inside drive 😧 installed by the pc manufacturer  prior to sales
looking inside the drive through the drive properties dialog box
it could say something like size 6GB , as mine does
If you then  look at the drive in windows explorer
the OEM backup is normally  marked as hidden and you cant see it
as to see it could be  to someone a possible delete it
providing the partition has not been deleted
or the OEM was not put there by the company
and instead gave you a disk,  'never happened in my case'
then the pc has all of this and should be found
you just need to  select 'show  hidden files'
I cant remember how you do that at the mo'  
then if its there you have your  original  restore vista system
which you can access from the boot screen
if  not ??????.
install windows 7 let it format the laptop drive and start again
else you wil be tied to that laptop for days

[#10]

coincidentally that brings back memories
these days i dont bother wasting time putting programs  on my pc
or games or whatever..  to fill up the hard drive
having to reformat this, that  because the pc wont run as fast  at it used too anymore
Now I just turn on the switch, read a little on the web and youtube it 
update vista and anti virus and still manage a  computer life 

[#11]

Windows is not presently suitable for the desktop.