Read about the same error somewhere and he said he resolved it with sfc /scannow.
Got a new error after I ran sfc /scannow and tried starting the postgresql service:
Can not start the PostgreSQL Database 8.3-service on Local computer.
Error 1053: The service did not respond correctly to the start- or sendcommand.
(translated from Dutch)
The postgresql log said the following:
FATAL: could not reattach to shared memory (key=1764, addr=01650000): 487
2009-02-20 02:15:48 CET LOG: database system was interrupted; last known up at 2009-02-20 00:04:52 CET
2009-02-20 02:15:49 CET LOG: database system was not properly shut down; automatic recovery in progress
2009-02-20 02:15:49 CET LOG: record with zero length at 0/496398
2009-02-20 02:15:49 CET LOG: redo is not required
2009-02-20 02:15:49 CET LOG: database system is ready to accept connections
2009-02-20 02:15:49 CET LOG: autovacuum launcher started
FATAL: could not reattach to shared memory (key=1764, addr=01650000): 487
FATAL: could not reattach to shared memory (key=1764, addr=01650000): 487
FATAL: could not reattach to shared memory (key=1764, addr=01650000): 487
etcetc.
Any ideas now?