Microsoft Security Essentials (MSE) is Microsoft’s free anti-virus program for personal use, and for businesses with 10 or less computers. Microsoft has indicated that is you already have MSE installed on Windows XP, then it will be supported and updated for another year, given that XP is no longer a supported platform.
To my surprise, I was at a client’s office on Wed April 16th and powered up two XP workstations. Both of them hung for the longest time right after logging in. Once they did come up, I was presented with various error messages about MSE. With no time to investigate, I went ahead and uninstalled MSE and then installed a different anti-virus program.
Today, I heard that the a bad definition file might have been the cause.