Acer aspire 5733-6838

In this case, it is recommended to perform a clean boot and check if any application or program is causing the issue. To perform a clean boot, you can follow the steps below:

For Windows 8.1
1. Swipe in from the right edge of the screen, and then tap 'Search'. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click 'Search'.
2. Type msconfig in the search box, and then tap or click 'msconfig'.
3. On the 'Services' tab of the 'System Configuration' dialog box, tap or click to select the 'Hide all Microsoft services' check box, and then tap or click 'Disable all'.
4. On the 'Startup' tab of the 'System Configuration' dialog box, tap or click 'Open Task Manager'.
5. On the 'Startup' tab in Task Manager, for each startup item, select the item and then click 'Disable'.
6. Close Task Manager.
7. On the 'Startup' tab of the 'System Configuration' dialog box, tap or click 'OK', and then restart the computer.

For Windows 7
1. Log on to the computer by using an account that has administrator rights.
2. Click 'Start', type msconfig.exe in the Start Search box, and then press Enter to start the System Configuration utility.
Note If you are prompted for an administrator password or for confirmation, you should type the password or provide confirmation.
3. On the 'General' tab, click the 'Selective startup' option, and then click to clear the 'Load startup items' check box. (The 'Use Original Boot.ini' check box is unavailable.)
4. On the 'Services' tab, click to select the 'Hide all Microsoft services' check box, and then click 'Disable all'.
5. Click 'OK', and then click 'Restart'.

One you have restarted your system in clean boot state, you can refer to 'What is next when I have a clean boot environment' section in the following link to know how to troubleshoot while in clean boot state:
http://support.microsoft.com/kb/929135

Hope this will help you.