Using MS default install directories

What is the conventional wisdom regarding the installation of Microsoft 32bit software O/S & otherwise in directories that are not the MS default?
For example
Would using non default directories provide an extra level of security against virii?
Could it provide extra protection from malicious HTML?
Can the directory names indicate to end users that they really shouldn’t be exploring this folder?
Do non-default names make for technical nightmares? If so how?

Any views are appreciated