If compressing your entire hard disk makes you apprehensive or you don't need that much added space, there is an intermediate solution:
zipping individual files or programs and storing them in compressed form either on a hard disk or on some other convenient medium.
They showed that brand-name recall under zipping conditions was 23 percent of normal-speed recall (i.e., zipping-speed recall divided by normal-speed recall).
Thus, we experimentally created familiarity by varying the number of normal-speed repetitions of the commercials before zipping.
As the number of previous, normal-speed exposures increases, the percentage of normal-speed recall/recognition will increase under zipping conditions.
This pattern of results will create an interaction between presentation speed (zipping and normal) and the number of previous, normal-speed exposures.
Under zipping conditions, there can be little persuasion due to learning new information and accompanying new elaboration.