Customizing the accessibility and ease-of-use settings of a computer can improve the overall user experience for people with and without disabilities. However, the adoption of such settings remains poor. This study investigates why various factors may influence people as they personalize and when they choose to integrate those changes into everyday use. To better understand how these factors may impact people's personalization process, we conducted a series of interviews involving 15 people with and without disabilities across several months in 2020 when computer usage became required due to the COVID-19 lockdown. We used grounded theory to analyze 49 semi-structured interviews with participants. During these interviews, people reflected upon: past attempts at personalization using built-in accessibility or ease-of-use features of their Operating System (OS) or other assistive technologies (AT), current customization activities using the personalization software, Morphic, and future opportunities for personalization systems and features. We identified several barriers, facilitators, and perpetuating factors that can influence why and when people choose to adopt and integrate their personalization changes. We also outline the overall personalization lifecycle, which illustrates when various factors may impact computer personalization. Personalization activities are complex and easily affected by an ecosystem of influential factors that surround them. When paired with the three design considerations and ten lessons learned from this qualitative study, the overall personalization lifecycle may be useful during the design and development of future personalization systems or features for people with and without disabilities.