I have a compaq P4 running XP and all of a sudden I can not install anything. I have tried the lastest version of windows installer I registared it and even tried taken the files from another good machine. I go back and forth between two errors. One is The Windows Installer Service could not be accessed. You may be running in safe mode or Windows Installer may not be correctly installed. The other is error msiexec.exe error. I am really at my wits end and don't know what else to try.