We recommend to accept the suggested default folder.
By default, QuickField 5.2 is installed into: <Your Program Files folder>/Tera Analysis/QuickField 5.2.
The files required to support QuickField protection key are always installed into: <Your Windows drive>/Program Files/Rainbow Technologies.
Professional and Student's versions of QuickField are by default installed into the same folder. However, the files that are different in these versions are installed into different places.
If you specify the destination folder containing another installed version of QuickField, the previous version becomes unavailable and you will not be able to uninstall it correctly.