Can i install the latest one (3.4.05) directly over my current one (3.3.03) or would i have to install and setup some older versions before coming to this new one?
If yes, then can somebody please make a chart of what other versions would i have to install?
You should make a backup of your current database, just to be on the safe side and then create a new folder. You should also shutdown your old version forum, by executing down.asp. You need to upload all the new version files to this new folder. Change config.asp to point to your current database and upload it as well. Then just run setup.asp. Of course, you can now change your old version folder name and the new version folder name, so that the URL for your forum does not change.
You should not, in any case, upload the new version files over the old version files, since this is not risk free, security wise.