I am currently SQLyog 4.0 Ent. I have downloaded SQLyog 4.01 Ent. The reason I ask is that I think that the Control Panel -> Add/Remove will show the two versions as been installed on Windows XP system. Then any subsequent uninstall will not be clean.
You don’t need to uninstall 4.0 Enterprise. V4.01 will upgrade itself automatically. You don’t even require entering any key information as v4.01 recognizes v4.0 key.
In Control Panel -> Add/Remove option, it will only show one application to uninstall i.e. SQLyog Enterprise.