a) Do you remember making any changes to your computer prior to the issue occurring?
b) Have you done an upgrade or clean installation of Windows 7?
Sticky Notes can be launched from the following location:
I would suggest you to perform an SFC scan and then check if you are able to use the Sticky notes.
Perform a SFC Scan
Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
If you are prompted for an administrator password or for a confirmation, type the password, or click Allow
Type the following command, and then press ENTER: sfc /scannow A message will appear stating that 'The system scan will begin'.
Be patient because the scan may take some time
If any files require a replace SFC will replace them.
You may be asked to insert your Win7 DVD for this process to continue
If everything is okay you should, after the scan, see the following message "Windows resource protection did not find any integrity violations"
After the scan has completed, close the command prompt window, restart the computer and check.
Check the below mentioned link for further guidance on
SFC scan -
After SFC scan you may fix the Corrupted User Account since the issue could because of Corrupted User Account.
Follow the steps from the article to fix Corrupted User Account :
If the issue persists I would suggest you to put the computer in clean boot state and then check if any non-Microsoft service is interfering –
To perform the clean boot follow the step 1 mentioned in the below article and then check in this clean boot state -
If the issue gets resolved check which non-Microsoft service is causing the problem; referring to the article and following other steps.
After you have finished troubleshooting, follow these steps to reset the computer to start as usual:
Click Start, type msconfig.exe in the Start Search box, and then press ENTER.
If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
On the General tab, click the Normal Startup option, and then click OK.
When you are prompted to restart the computer, click Restart.
Azeez Nadeem - Microsoft Support