After booting in safe mode.
Go to Start->Run>Msconfig
Now remove many unimportant services for the timing but check Windows Installer service, then reboot the system. Boot it in normal condition. Then you can continue the process of uninstalling the application.
2. REGISTRY PROBLEM?? Have u suffered the problem.. Registry not found or Error in registry in that type of problems. the best thing is to replace current with backup copy. Like LAST KNOWN GOOD CONDITION at startup menu of windows or if you have system restore then restoring to the older point will help you a lot. The registry problem can occur if you have'nt installed the software properly. For this Unistall the related software using step 2 :)
If the problem not solved. Then REINSTALLATION CAN ONLY HELP IN MANY CASES.
3. SYSTEM FILE MISSING or related: It can be solved by many ways.
1. Start->Run->SFC then check for alter file scan or just write the file name and give them the setup path.
2. Search for file, if found send it to desired folder(WINDOWS,SYSTEM or SYSTEm32 in general)
3. Above not working, Restart the system in command prompt only mode. Go to the setup directory. and write
"extract/a" then starting cabinate file name e.g. DRIVER11.cab then desired file name. The file got extracted, then send it to the desired folder