simmo,
Do you have a Dell system?
This problem is most likely caused by an unwanted registry entry. These type of entries can be caused by an improper or incomplete program removal, or a virus that wrote to, or tried to write to the registry.
Firstly, are you using an anti-virus? If so, which one?
Run a full virus scan
If you do not have an anti-virus.....I would run an online scan until I get one installed.
Secondly, are you using anti-spyware such as Adaware or Spybot SD? If so, run them.
If not, get them.
Easiest way to determine the culprit is to examine the Startup list in MSconfig. Shut down all the programs that you cannot positively identify and see if the problem still occurs. If so, continue shutdowns until you only have only Stimon and Systray listed. This should identify the "offending" line. Once you have it, let me know what it reads and we can take corrective measures.
If this method fails, we will continue troubleshooting.
PS: If you attached a jpeg of your regedit, it did not attach.
Let me know what your results are to the above.
Techie