Symantec says you can ignore this:
You see the following message after you run a WinDoctor diagnostic scan from within Norton SystemWorks:
Missing file: "C:\Program Files\Common Files\InstallShield\Professional\RunTime\0700\Intel32\DotNetInstaller.exe" cannot access a necessary file, "mscoree.dll."
This message can safely be ignored. InstallShield is not really trying to use the file DotNetInstaller.exe without .NET Framework being installed. The DotNetInstaller.exe file is merely cached in the engine location for future use.
Follow the steps below to ignore the problem reported in WinDoctor.
To prevent Norton WinDoctor from repairing the problem
1. Open Norton WinDoctor.
2. If the Norton WinDoctor Wizard does not start automatically, then in the main Norton WinDoctor window, click Scan.
3. In the Norton WinDoctor Wizard window, select "Perform all Norton WinDoctor tests (recommended)."
4. Click Next.
5. When WinDoctor has finished checking your system, click Next to examine the results.
6. Click Finish.
7. In the main Norton WinDoctor window, click the Problems button.
8. Under Problems Found, click the problem for the missing file, mscoree.dll.
9. Right-click the problem for the missing file, then click Problem Details.
10. Under Details, right-click the entry you want ignored, then click "Ignore Selected Problem."
11. Click Repair All > Yes to continue.
12. Exit Norton WinDoctor.
Each time you run Norton WinDoctor, this problem is ignored.