Something has been left out of your post. Often when I read the words you've written, the user has run DrWatson and has done some preliminary digging and has come up with some reference to mstask.tsk. Be that as it may, there is NO "do-this" answer for what you've posted. To add more insult to Windows ME users, Microsoft removed the various OS repair tools such as SFC so we can't do much but simple things. I will post my usual that no PESTS be allowed on the machine since that has been a key item found in posts like yours.
http://reviews.cnet.com/5208-6132-0.html?forumID=32&threadID=1313&start=0 notes the five scanning tools and removal tools that are fairly safe. If one does encounter an issue, its always been damage done by the MALWARE. The most common issue being Layered Service Provider replacement which you can use LSPFIX (Hint: use http://www.google.com to find).
The thread has follow on discussions about new links if you don't want to use Google to find an item.
PS. All the tools are free.
I have a Compaq Presario 5008CA, the 5000 series and am operating the Windows Me operating system. The problem is, my Start Menu and Taskbar are giving me troubles. What I'm trying to do is, exit the mmtask.tsk module to fix the Taskbar and Start menu problem, hopefully. Can anyone advise me on how to exit this module, please?