Setup has detected a non canonical discretionary access control list (DACL)
on directory ‘c:Program FilesMicrosoft SQL Server100DTS’. Please veirfy
your security settings and make corrections if needed.
Its ultimately a security issue that seems to result from having 1 version of SQL Server installed (in this case SQL Server 2008 Express) and then installing another instance in addition to it (in my case, SQL Server 2008 Developer). Something happens with the directories that the two instances share that causes a security problem.
If you navigate to the directory in question, right click it, and open up the security options tab, you’ll likely find that the account you’re logged in as doesn’t have full control over the directory. Edit the settings for your account to have full access and you should be good to go.