Oracle 10 g xe plsql connection database package ora-12541 error

I solved this problem through the following address:
http://jingyan.baidu.com/article/a3761b2b8d3d391576f9aa15.html


I changed the computer name of my own computer, which caused the oracle server monitoring service to fail to start.
Click Start to stop immediately.


It can be solved by modifying the host name monitored by listen.ora