If the higher version works, you can indeed simply delete the lower version folder, in my experience. Leave it in the recycle bin until you're sure.
In Security forum http://reviews.cnet.com/5208-6132-0.html?forumID=32&threadID=165192&messageID=1827619
Marianna Schmudlach writes
''You MUST do this as part of the cleaning process
go to http://www.java.com/ & download the latest version of java 188.8.131.52 install it & then go to add/remove programs and UNINSTALL ALL previous versions of sun java''.
I have a corrupt Add/Remove
I have ''Java 2 Runtime Environment SE 1.4.2 entry in Add/Remove but NO ''Remove'' button and NO folder for this version in the registry...\CurrentVersion
\Uninstall\<Program Name string>
I installed the newest version of Java and have a Remove button for it. In C:\Program Files\Java I have now 2 folders jre1.5.0_06 and old j2re1.4.2
Could I simply delete the j2re1.4.2 folder and clean what's left with CCleaner?? What could be the consequences of this action?
I dealt with corrupt Add/Remove by reinstalling the majority of software but do not know how to deal with this.
I have Win XP sp2 with all the relevant updates, use Firefox, Zone Alarm and have all the recommended antispyware ( AdAware SE, SpybotSD, Spyblaster, Ewido, Windows Defender ) and CCleaner installed.