Microsoft Security Essentials is a free security product by Microsoft for Windows XP, Vista and Windows 7. While that is a good thing, it is also one of the weaker programs in terms of protection.
Still, it appears to be a highly popular choice for users of those systems, likely because it is produced by Microsoft, and because it is easy to use.
Our suggestion would be to switch to another product, like Avira Antivirus, which is also available as a free version.
If you are using Microsoft Security Essentials and noticing that it impacts your PC's performance, especially during scans, then you may be interested in the following tip to reduce the load that the software has on your system.
Here is what you need to do to achieve that:
- Open Microsoft Security Essentials on your PC and switch to the Settings tab in the program interface.
- The first thing is to change the maximum cpu cycles that the program may use during scans. The value is 50% by default, which you may want to reduce to 10% instead. While this may prolong the overall scan time, it ensures that resources can be used elsewhere during scans.
- What you may also want to consider is changing the day and time of the scan. If you do not want the program to scan your PC each Sunday at around 2:00 AM, change that to a day and time that better fits your work schedule.
- MSE will only start scans if your PC is on but not in use, and I'd recommend you keep that setting enabled.
Side-tip: If you want scans to complete faster, remove the "limit cpu usage during scan" check-mark to achieve that.
The second thing that you can do is change the process priority of the msseces.exe process in Windows. Tap on Ctrl-Shift-Esc to open the Task Manager, switch to processes, and find the process listed here.
Right-click on it and select Priority > Below Normal or Low instead. Note that this is only valid for the current session.
If you want the change to be permanent, download a free program like Prio for that. You can use Prio to set the process priority of any process to another value, and have it retain that new value even between sessions.