What is postgresql status? I'm not sure

Hello all,
Don't shoot me, I'm just the fella sweeping up after a departure.
I'm supporting a web site with mapping features using Mapserver and PostgreSql 7.5 for windows.
Recently, my mapping features went down.
Error messages that display are the following...

Warning: pg_query(): Query failed: ERROR: xlog flush request 0/34D85078 is not satisfied --- flushed only to 0/34CD4518 CONTEXT: writing block 0 of relation 394198/412173 in C:\ms4w\Apache\htdocs\davison\mapping\gis1\viewparcel_nolink.php on line 10

Warning: pg_fetch_row(): supplied argument is not a valid PostgreSQL result resource in C:\ms4w\Apache\htdocs\davison\mapping\gis1\viewparcel_nolink.php on line 12

It looks to me that the query failed based on a hard drive issue. Well, over the weekend we swapped out the hard drive for new. The site comes back fine but I'm still receiving the error.

Another notice is when I shutdown and restart the database, I get this...

C:\ms4w\apps\pgsql75win>cd c:\

C:\>cd ms4w/apps/pgsql75win/data/

C:\ms4w\apps\pgsql75win\data>del postmaster.pid
Could Not Find C:\ms4w\apps\pgsql75win\data\postmaster.pid
LOG: database system was shut down at 2011-08-24 17:30:14 Eastern Standard Time

LOG: checkpoint record is at 0/34CD4078
LOG: redo record is at 0/34CD4078; undo record is at 0/0; shutdown TRUE
LOG: next transaction ID: 1198832; next OID: 1772830
LOG: database system is ready

I'm not sure if the database is up or not.
I don't even see postgresql or mapserver as Windows services.
I'm very confused.

Thank you for any help with this continuing problem.

John