After cleaning the registry with Registry First Aid, I find a program does not function correctly. What do I do?

The best way to figure out a problem registry entry that should not be modified is to correct all invalid registry keys found by Registry First Aid, then re-install the problem software, be sure that it works and scan the registry with Registry First Aid again. More likely, the program will find some new invalid registry entries and some of them will belong to the problem software.

From this moment you can correct every single invalid entry (with creating separate backup files) and test your software after every single correction. If the program doesn't work after last correction then that registry entry should not be modified. Restore it from the last created backup .reg file. Be sure that the program works fine again and add that registry key into the Excluded list.

In this way you will able to find one or more registry entries that should not be modified. Add those entries into the excluded list using the right-click pop-up menu over the selected entry.

If you feel you don't want to take the time to do this deep test, you can simply add into the exclusion lists all of the new found registry entries after re-installing your problem software.

If you don't have the installation program for the problem software or the above instructions do not help, you can do the following.
  1. Restore your most recent backup .reg file.
  2. Check if the problem still exists.
  3. If the problem exists then restore your next .reg file created before the most recent one. Restore .reg backup files one-by-one in backward order (from the most recent file to the oldest). Test for the problem between restoring the backups. Do these steps until you find that the problem disappeared.
  4. If the problem has gone this means that the latest restored .reg file contains a modified registry key that caused the problem. Please send that backup file to support. If the problem persists then you can restore the most recent full registry backup file. If that doesn't help then the problem is not coming from a damaged registry.
Next steps:
  1. Scan the registry with the program.
  2. Select for correction only first 10-20 found invalid entries and correct them.
  3. Reboot the computer and check if there is no problem.
  4. If computer works OK then scan the registry and correct next 10-20 invalid entries. Do the steps 5-8 until you find that the problem re-appeared.
  5. If the problem re-appeared then the most recent .reg backup file contains the problem registry key within 10-20 modified entries.
  6. Restore that backup file, scan the registry and correct invalid entries one- by-one with checking your system functionality between corrections.
Following this procedure you will figure out which problem registry key should not be modified. Add that key into the exclusion list - right mouse click on the selected key in the list to pop-up menu and click the Add the Entry into the Exclusion List menu item.

-OR-

After you have restored your program functionality please scan the registry and try to find within found invalid entries a registry key that corresponds to the problem program. Usually it looks like 
HKEY_LOCAL_MACHINE\Software\your_problem_program_name\....
Unselect all of the found entries, pick only this entry and make changes to the registry, by creating an individual backup file like 
C:\Program Files\...\trouble_1.reg
Then run your program and check if it functions properly. If it runs OK then restore that corrected entry and try to find another problem entry using the previous method. When you find the problem entry (after correcting it, your favorite program stops working), add the entry to the Exclude List.

After that run the registry scan, make registry changes and be sure that your program works OK (the found problem entry will be excluded from the registry scanning).

This problem finding algorithm is useful for all faults that may appear after repairing the registry using Registry First Aid.

Please, also take the time to send your found excluded registry entries with a detailed description of the problem (what applications do not start, do not work properly, etc.) to support. This will help us to help you to avoid the same problem with future versions of the program.

Running Registry First Aid once a week in the future will decrease the number of invalid registry entries, and correction will not be a problem.