How to clear registry manually in Windows?

I have installed postgreSQL in my pc.

Unfortunately, it doesn’t connecting database.

Now, at my reinstalling, the same problem occurs. This can be solved by cleaning registry.

Can I clear it manually ?

A word of warning: Be very careful with editing the registry! It may turn your Windows installation unusable pretty fast.

Now that this is out of the way:

1. Open the Windows start menu.

2. Enter regedit in the search field (Vista/7) or the “run command” field (XP)

3. Enjoy. You can search the registry (Edit > Search) for strings containing “postgres”.

However, I agree to Mehper, that you should first find out what to change exactly before just digging through the registry.