Haunted Computer/Mouse

Randomly at various points throughout the day, no matter what I'm doing my computer mouse goes crazy and starts moving about the screen and clicking/dragging dropping items.

I have Sophos antivirus - running in the background and performing daily checks
I have run Spybot and is now running in the background
There are no remote software programs on the machine
I have tried 3 different mice (wireless, wired but only USB as I dont have a green mouse connector on the back of my PC).
I am using a wireless keyboard (cant seem to find a wired keyboard which has a USB connector in the office...). The keyboard is fine but for good measure I have changed the batteries.

I have been using the wireless keyboard & mouse combo for about 5 months without any problems and recently got a second hand base (work computer). Have changed batteries repeatedly in mouse and now no longer use the wireless mouse but I still get mouse wireless signal strength warnings.

As I haven't got the green connector I'm limited to testing optical mice and have changed the surface numerous times (nothing, mouse mat, paper of varying colours just in case...)

It's not when I'm using any specific program either; I'm usually running the following programs regularly:
Outlook
AutoCAD
Chrome
Word
Explorer

ANY ideas? This is driving me nuts!!!

 

I have also vacuumed PC and keyboard - this made no difference
Tried the obvious of using different USB plugs - made no difference either.

 

It almost sounds like someone is taking control (RDC of some form). Does this issue occur in Safe Mode (not safe mode w/networking)?

Also try READ & RUN ME FIRST. Malware Removal Guide: http://forums.majorgeeks.com/showthread.php?t=35407

-This is an very well written extensive thread explaining the removal of malware from your machine

 

Go into Control Panel, Admin Tools and Services and turn off Remote Services!
Here's a step by step
http://www.ehow.com/how_5128005_stop-remote-desktop-service.html