The installation process for PostgreSQL can be challenging for new users due to several factors. A common issue is the requirement to set a strong password for the default 'postgres' user, which users often forget, leading to a complicated reset process. Another challenge is port conflicts, as PostgreSQL uses port 5432 by default; if another application is using this port, it complicates installation. Additionally, users must configure PostgreSQL to be included in the system PATH for command-line operations, a step that is frequently overlooked, causing frustration when executing commands.