100% CPU usage

Am using WIn2k Professional , in that when i access a a secured site using https// i noticed that my system was going very slow. i had other applications like outlook & word opened. when i went to TASK MANAGER to check the CPU usage. i found that IExplorer was taking 100% of CPU time.

is this causing a slowness ??

why Iexplorer alone is taking 100% of CPU time ?how do i solve thsi problem ??