Upgrade Windows 7 Home Premium RC To Windows 7 Ultimate Retail version

[New buDDy]

Hi,
Currently in my laptop I am using Windows 7 Home Premium RC. Now I want to upgrade it to the retail version of Windows 7 Ultimate. I need some information on the same. Here what will be better. Clean installation of Windows 7 or upgrade. If I just upgrade then what all changes I will have to maintain in the system. Thanks

[Solomon]

First it is very necessary that you must have Windows 7 Home Premium in your system. Just ensure it first. Normally by default the RC is the ultimate version. You will just need to remove the ei.cfg file from the image file of Windows. Install the same after that. This will not work on any other version.

[MrChris-]

Follow the instruction here to get the work done. First insert the windows disk and copy the entire disc content on your computer. Then open the source folder in the disc. After that look for cversion.ini file. Open it and change the first number to 7077.0. Save the file. By this the upgrade is done already. Then if you need to downgrade the same edition, here you will need to edit the registry.

[Calvin K]

In order to do this you have to first bypass the version check. To do this you will have to edit Cversion.ini file from the installation image. To do the same first download the ISO version of the same operating system. In the file search for the above named text file. Edit the following in it -
[HostBuild]
MinClient=7000.0
MinServer=7100.0
Save the file in the same location and run the setup.