Big thing for corporations is users being aware that they're not free to go downloading stuff and installing it.
Can be anything as simple as WinRAR, a text editor, even FireFox - in the main programs such as these are free to use as intended for single 'home' users, and are licensed that way. (often the readable bit u click "Agree" to without reading)
However, firms, companies, corporations etc generally are required to have licenses for them that are suited to their business environment.
Many companies will audit computers for installed software, some even use a "bot" (for want of a better term) that will check computers on a network for approved software and uninstall those that aren't allowed. Stuff found on a bigger scale can bring further action depending on the situations.
Establishments like FAST do grade companies, and have a willingness to check that companies are within regulations regarding licensing (in their various forms) - and they do assign grades in the form of gold/silver/bronze/something to companies which they have experience with and.. if u like.. determines how much they may be willing to stick their nose in ur business, to crudely put it.
Apart from the downloading/installation of software and it's legalities to a firm, there's also the issue of these things contributing to OS failiures - which ofc leads to costs in terms of the local IT having to fix/rebuild.
Software as described above can in 99% of the cases be used by the user if they have a need/work reason for having them. This often comes in the form of a 'request' that begins a procedure of either purchasing, allocating licenses or an IT guy installing stuff - in the main, at this point, within the approved library, all the licenses 'should' be legit and software tested against the OS install the company uses. Can take some time depending on circumstances. I say 'should' as even the best of "Gold FAST" regarded companies do have to police themselves as having 1000s of installs of Nero7 isn't good when u have a license for 950. OR ur lcense only applies to Nero6.6 currently - even if it's an OEM cd install.