MINIMUM SYSTEM REQUIREMENTS
Pentium 233-megahertz (MHz) processor or faster (300 MHz is recommended)
At least 64 megabytes (MB) of RAM (128 MB is recommended)
At least 1.5 gigabytes (GB) of available space on the hard disk
Windows Vista and Windows 7
1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor
1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)
16 GB available hard disk space (32-bit) or 20 GB (64-bit)
DirectX 9 graphics device with WDDM 1.0 or higher driver
Although no sensible IT department would ever try and run computers on bare minimum requirements, what the official specifications reveal is that the requirements have increased to between 4 and 10 times what they were previously.
For most companies, this means having to scrap old computers, and buy new ones if the "software upgrade" is not to become a "performance downgrade".
TIME AND EFFORT
It should not be underestimated how much time and effort is required to test and deploy a new operating system on hardware it was not designed to run on.
In the past, IT departments would simply buy a new computer with the new operating system already installed.
Now that budget reductions and spending reviews are happening, the rip-and-replace mentality of old is no longer acceptable to most businesses, and new ways need to be found to keep computers running the right mix of software, at a price the business is willing to pay.
Modern software is written with the assumption that organisations are moving to new computers and laptops fitted with 64bit processors.
A computer with a 32bit processor cannot run a 64bit operating system, or 64bit applications under normal circumstances.
Desktop Virtualisation can be used to allow a 32bit computer to run 64bit software without making any expensive hardware modifications or upgrades.