Symptoms

While installing ubuntu ,it’s very slow ,usally it took long like 3-4 even 5+ hours to finish the installation.The progress was showing “Retrieving file” with several hours remaining

Cause

The reason is the installation was updating ubuntu to the latest for you , and because you are located where the network latency is high while connecting to the main ubuntu repository. Or normally after you finished the installation you usally changed sources.list to use local ubuntu repository mirror which is faster

Resolution/Workaround

The workaround is to disconnect your laptop or desktop pc or vmware from network , then install ubuntu ,after the installation is been done, change your repository to one mirror which is faster

If you are installing ubuntu via vmware player , you can disconnect the network before installation refering below screenshot , untick the Connect at power on option

Conclusion

If you are suffering slow ubuntu installation , you can try to disconnect the network of the installing ubuntu , then the installation will not update ubuntu during the installation for you and you can do it post-installation.