How to Fix Installer Error 1001 – Here is the Fixing Guide

Are you unable to install or uninstall any program on your windows PC due to the following error:

Error 1001 InstallUtilLib.dll

MSI install exception occured error 1001

Error: 1001. An exception occurred while uninstalling. This exception will be ignored and the uninstall will continue. However, the application might not be fully uninstalled after the uninstall complete.


There are so many reasons behind installation error 1001 like Damaged or Corrupted System files, Missing DLL file, system recovered from virus/malware attack, incomplete installation of software, improper shutdown the PC, wrong entries in registry file etc. Here, I am giving some useful way to fix installation error 1001. Try each method one after another and examine whether the error got fixed or not.

Method 1: Fix using Advanced System Repair Tool

The most of the common reason behind program install failed is corrupted or damaged system files like DLL files, EXE files, sys files etc. There are thousands of tiny system files are there that work specific task. If one of the files gets replaced, deleted or damaged then you may get windows installer error 1001.

Windows is made with huge number of dll files, exe files, sys files, various types of services, databases, etc so, it is not possible to keep monitoring all the files always. A brilliant PC Optimizer tool repairs damages, fix errors, update windows and drivers, and eliminate various types of errors silently.

Outbyte PC Repair Tool does all the above task easily and provides you an errorfree and smooth Windows environment to work so that you can focus on your business only.

3 Steps to Fix this Error
Step 1. Download Outbyte PC Repair Tool [File Size: 16.4 MB]
Step 2. SCAN your Windows PC
Step 3. Click Fix button to Repair Error

Download and Install Advanced System Repair Tool and scan your PC. It has the large database with 25 million of files. It will find all the damaged or deleted system files and reinstall them with the fresh one. After, optimizing with Advanced System Repair Tool, try to install software again.

Method 2: Run System File checker.

System file checker is an inbuilt tool in windows that scans whole system files and repair them if problem found. It is very easy to use this tool. Just open command prompt as administrator and type following command and hit Enter.

sfc /scannow

sfc scannow

Method 3: Apply Clean Boot

You may also try Clean Boot to install the software. When you open your PC in Clean Boot mode, the system gets started with only minimal services and tasks. Here, is the detailed guide to start your PC in clean boot mode.

Method 4: System Restore

If you have created System Restore Point earlier than, this solution might be life changer for your PC.

1. Open Start menu and type System Restore in search menu.
2. Select Create a System Restore Point in Search menu and open it.
3. Now go to System Protection Tab and then click System Restore button.
4. Now, follow the screen instructions and select appropriate restore point and click Next.
5. Let the process finish and Reboot your PC.

Most of the time by installing and uninstalling various softwares, replace the system dll file and raise error 1001. But when you restore your PC with earlier point, the problem gets finished.

Method 5: ReRegister Windows Installer Services

Re-Registering Windows Installer Services Resets all the settings and fix the problems.
Step 1: Open Run Dialog Box by pressing Windows Key + R simultaneously.
Step 2: Type MSIEXEC /UNREGISTER in Run Dialog box and click OK. This command will display nothing but unregister the Msiexec.exe file.
Step 3: Open Run Dialog box again and Run the following command to register Msiexec.exe file again.
Step 4: Restart the PC. Before restarting, you must bookmark this article for further support.


In this tutorial, I have tried to tell you some useful methods to fix windows installer error 1001 on your PC. As situation defers on your PC configuration and installed software, you must use Advanced System Repair to automatically fix this error.

Leave a Reply