I have Pega 8.7 personal edition. Error while installing 

log files are below...

Targets:Initialization,Database Server Installation,Data Load,Configuration,PRPC Launching Buildfile: C:\Users\gasrinu\Downloads\117149_PE_8.7\.\pegaGuiInstallerTemp\build.xml

Initialization:      [echo] Beginning installation of Pega Platform 8.7.0 Personal Edition -- this process should take about 5-10 minutes ...     [mkdir] Created dir: C:\Pega8.7\PRPCPersonalEdition     [mkdir] Created dir: C:\Pega8.7\PRPCPersonalEdition\temp     [unzip] Expanding: C:\Users\gasrinu\Downloads\117149_PE_8.7\pegaGuiInstallerTemp\PersonalEdition.zip into C:\Pega8.7\PRPCPersonalEdition      [echo] Configuring Tomcat (Setting Java Home and Catalina Home)...   [replace] Replaced 0 occurrences in 0 files.   [replace] Replaced 1 occurrences in 1 files.   [replace] Replaced 2 occurrences in 1 files.   [replace] Replaced 1 occurrences in 1 files.

Database Server Installation:      [exec] The files belonging to this database system will be owned by user "gasrinu".      [exec] This user must also own the server process.      [exec]       [exec] The database cluster will be initialized with locale "English_India.1252".      [exec] The default text search configuration will be set to "english".      [exec]       [exec] Data page checksums are disabled.      [exec]       [exec] creating directory C:/Pega8.7/PRPCPersonalEdition/pgsql/data ... ok      [exec] creating subdirectories ... ok      [exec] selecting default max_connections ... 20      [exec] selecting default shared_buffers ... 400kB      [exec] selecting default timezone ... Asia/Calcutta      [exec] selecting dynamic shared memory implementation ... windows      [exec] creating configuration files ... ok      [exec] Execution of PostgreSQL by a user with administrative permissions is not      [exec] permitted.      [exec] The server must be started under an unprivileged user ID to prevent      [exec] possible system security compromises.  See the documentation for      [exec] more information on how to properly start the server.      [exec] child process exited with exit code 1      [exec] initdb: removing data directory "C:/Pega8.7/PRPCPersonalEdition/pgsql/data"      [exec] running bootstrap script ...       [exec] pg_ctl: directory "C:/Pega8.7/PRPCPersonalEdition/pgsql/data" does not exist      [echo]       [echo] Waiting for Postgres to start... Unable to connect to database -- will retry in 1 second... Unable to connect to database -- will retry in 1 second... Unable to connect to database -- will retry in 1 second... Unable to connect to database -- will retry in 1 second... Unable to connect to database -- will retry in 1 second...