You need to obtain the 8.1 Enterprise media for the upgrade:
http://www.microsoft.com/en-us/windows/enterprise/default.aspx

Run Windows Genuine Advantage diagnostic tool from the following link and post the results here:

http://download.microsoft.com/download/9/F/3/9F3DED28-A521-4352-B8A4-20368D0CC1AA/MGADiag.exe

Hi Balaji, thanks for the reply.

Ran the tool you gave me the link for and this is what I have got. I could not copy and paste as it kept coming up with an error message when trying.

Validation Status:   Validation unsupported os

Validation Code:  6

Product Key: *****-*****-*****-*****-*****

Product Key Hash: gA8osW56LiA1ZSWnb9g+f4pqeIo=

Product ID:  00190-70000-00001-AA235

Product ID Type: o    unknown

Windows OS Version:6.2.9200.2.000103000.0.0.101

ID: (FF3EA33DB-ACB3-4EC0-A904-16BO88632431}(3)

Administrator: yes

TestCab: 0x0

Legitcheckcontrol:  NA,hr = 0x8007002

Signed By: NA, hr = 0x8007002

Product Name: Windows8

Architecture and Build: 0x00000009         9200.win8_gdr.140502-1507

TTS Error: N/A

Validation Diagnostic:

Hope this helps and what do I do now.

On an other note, while checking my system I see my windows licence is due to expire on the 20/10/14. Can you possibly tell me why this is??.

Thanks again for your help.

Regards

Kellybhoy.

If you installed the evaluation of Windows 8, it would have been the Enterprise version, and would have expired in 90 days.  Enterprise cannot be upgraded through the Store.  You can "re-arm" your evaluation to extend it, but it cannot be converted to a permanent license.  Permanent Enterprise licensing must come directly through Microsoft's volume/open licensing model and cannot be purchased otherwise.

Hi Balaji,i have  been away a wee while so just getting around to replying to everybody. I have opened the link you posted but it won't let me copy it. I would need to type it all out manually, and will do, but first i have to ask you another question.

I bought this home computer with windows 8 preinstalled and like any other computer i have bought i was under the impression that the OS was paid for and installed forever with all the updates included. So, why does my Home computer keep telling me that my version of windows 8 is volume licensed? I thought volume license was just for buisness users.

Thanks in advance

  JK.

The volume license is just for business users and shouldn't be preinstalled with a computer.

I assume you never bought the system direct from Dell but instead bought it via the likes of ebay or gumtree? If so its possible the seller sold the system without genuine Windows.

Please provide the model number of this system and also run RWEverything:

http://rweverything.com/

Select Access → ACPI Tables → MSDM Tab

If there is no MSDM Tab then this system does not have a Dell Windows 8/8.1 OEM SLP key.

Also let me know if the system has a Windows 8 sticker or Windows 8.1 sticker affixed to it which look like these:

Alternatively if it has a Windows 7 COA:

The COA may be present under the battery compartment.

Hi Natakuc4 , thanks for your help. I bought the system direct from Dell, still have the invoice and paperwork.

I ran the link you gave and it has a MSDM tab. It also has the purple coloured  windows 8 sticker. The model is the desktop xps 8700. I can't seem to ask anyone at dell as there seems to be no contact or email details anywhere on the net.

Thanks again.

  JK

Right so it has a genuine Windows 8.1 license. Please follow the instructions here:

http://dellwindowsreinstallationguide.com/download-microsoft-windows-and-office/download-microsoft-windows/download-windows-8-1-retail-and-oem-iso/

Try first with the "Windows 8.1" Edition and secondly with "Windows 8.1 Single Language Edition". The correct Edition will take you to the license agreement screen the incorrect edition will ask for a product key.

Hi Natakuc4, thanks for the reply. When i go into system, basic info is telling me that it has windows 8, not 8.1.

It does not have an OEM and as windows came perinstalled i did not recieve any confirmation email or retail packaging. I downloaded rweverything and found a product key there. However, when i click the link in system, "get more features with a new edition", i see the last five digits of the current product key and these are different from rweverthing digits. It also tells me my licence to use windows expires on the 4/5/2015.

I getting a wee bit confused now, all i wanted to do was upgrade from 8 to 8.1. Any suggestions appreciated.

Regards

 jk

Follow the instructions in this video:

http://dellwindowsreinstallationguide.com/download-microsoft-windows-and-office/download-microsoft-windows/download-windows-8-1-retail-and-oem-iso/

Try the "Windows 8.1" .iso. Make a FAT32 UEFI Bootable USB set for the GPT partition scheme. Boot from it, let me know if you are asked for a product key. If you are its the wrong Edition for your license. If you are its the correct Edition.

If "Windows 8.1" is the wrong "Edition" try the "Windows 8.1 Single Language" .iso. Make a FAT32 UEFI Bootable USB set for the GPT partition scheme. Boot from it, let me know if you are asked for a product key or whether you are taken to the license agreement screen.

You have a purple Home sticker so it should be one of these two Editions and an XPS 8700 is too high end to have came with any of the Bing Editions.