Hi MJBALTIC and welcome to the Community

I'm using an Advent PC and can't upgrade yet either, so it may not just be Sony.

Mind you, Sony advises all Vaio users not to upgrade at the moment anyway.

Have you had a look at the Windows 10 Upgrade page on the site Here?

Also have a look at the Windows 10 'Alerts' page Here.

"WARNING: There is a risk of software/driver corruption. We therefore strongly recommend that you do not upgrade to Windows 10 when it becomes available on July 29.

Sony is now testing Windows 10 and will be providing compatibility information during the summer of 2015. The release schedule will vary according to the different products.

With regards to Sony VAIO personal computers, we are preparing a Windows 10 upgrade procedure – together with the necessary drivers and software* – for compatible models released after October 2012 (which were delivered with the Windows 8 or Windows 8.1 operating system preinstalled). Please note that Sony is currently not planning on providing an upgrade procedure, nor drivers and utilities, for older models which were released with Windows 7 or previous versions of Windows preinstalled.

Please wait until the upgrade information is released. Visit our support website regularly for the latest information and updates about this topic.

*Note that some of the functions, utilities or other software on your computer might be missing or not working properly after the Windows 10 upgrade."

They really aren't ignoring Vaio users, in fact quite the opposite as they are still testing.

I realise It may not be ideal for you but it is safer for you and other Vaio owners to wait until all the drivers etc. have been sorted out instead of corrupting drivers / software.