My daughter's Compaq Vista laptop has developed a bad problem. The CPU usage is stuck on 100%, making it very slow to use the machine. What I find hard to understand is that in Task Manager the only process using any CPU is taskmgr itself, which is using about 10%, but the total usage shows as 100%. Are there processes that do not show up in Task Manager? I have just run sfc /scannow, which looks for corrupted system files. On completion is said that there were errors but they could not all be repaired. I looked at the log file, CBS.log, which has hundreds of lines that don't mean much to me. Any suggestions?