First check your mouse settings. Then try your mouse on another machine. If it's a ball mouse, clean it. How to clean; http://www.google.com/search?q=clean%20ball%20mouse&sourceid=groowe&ie=utf-8&oe=utf-8
Its possible that you have something like GATECRASHER INTERNET TROJAN HORSE PROGRAM running in the background. http://www.privsoft.com/archive/psc-gc.html
It will be running in the background, and it can do the very things you speak of;
CAPABILITIES:
The GateCrasher server permits anyone using the GateCrasher "GC - client.exe" client on their end to remotely control the victim's machine. GateCrasher is a risk to all Win32 platforms including Windows95, Windows98 and Windows NT. When received as a document, any machine running Word97 will install the infestation on the victim's machine as soon as it is opened.
It can be configured to run on any port but the default version is configured to listen on port 6969 and respond on port 139 unless changed. Privacy Software Corporation has already received reports of this and similar trojan horse programs from BOClean customers in actual operation on their machines. We quote from the documentation shipped with GateCrasher below verbatim:
* Connect - Find someones IP and put it in the 'Host:' box then press 'Connect'
* Disconnect - Simply press the 'Disconnect' button
* Hide/Show
* Hide Mouse - Hides the servers mouse pointer
* Show Mouse - Shows the servers mouse pointer
* Hide Taskbar - Hides the servers taskbar
* Show Taskbar - Shows the servers taskbar
* Open/Start
* Start Program - Start a program
* Open WebBrowser - Opens the default Browser
* Open Control Panel - Opens Comtrol Panel
* Open Date/Time - Opens the Date/Time
* Open Appearance - Doesn't work yet
* Start Screen Saver - Starts the screensaver
* Open CD - Opens the CD
* Close CD - Closes the CD
* Get Owner - Gets the username of the person logged into Windows
* Get Computer Name - Gets the computer name
* List Files in Directory - List the files in the specified dirctory
* Delete
* Delete File - Deletes the file in the 'Extra Data...' bar
* Reboot Computer - Reboots the server
* Delete Directory - Deletes the directory in the 'Extra Data...' bar
* Clear Recent Folder - Clears the recent folder.
* Close
* Close Windows - Shuts down server
* Shutdown! - Shuts down the server
* Log Off - Logs off Windows if there are multiple users
* Misc
* Read From Drive A: - Shows the files on Drive A
* PING! - Pings the server
* Send Text - Sends text
* Make Directory - Creates a directory on the server
* Get OS - Tells you the operating system on the server
* Get Free Space - Tells you how much free space is on the servers Hadr Drive
* Get Disk Serial # - Tells you the serial of the specified disk
* Send/Get
* Send Message - Sends the server a message
* Get Windows Directory - Shows the contents of the Windows Directory
* Get Temp Dir - Shows the Temp Directory
* Search for file - Searches for a file on the server
* Get HD Letter - Tells you the servers hard drive letter
* Get Local time - Shows the servers local time
* Get Active Windows - Shows all active windows on the server
* Switch Window - Makes the selected window the active one
* Get System Directory - Shows the contents of the Windows\System directory
* Set Computer Name - Sets the computer name
* Get User - Shows the name of the current user
* Crazy Mouse Start - Makes the mouse pointer move by itself
* Crazy Mouse Stop - Stops the mouse pointer moving by itself
* Get Organisation - Gets the organization of the server
* Kill Window - Closes the specified window
* Set Volume Label for C: - Renames drive C
Read it all here; http://www.privsoft.com/archive/psc-gc.html
Make it a great day!