Windows cannot load the user’s profile b

hi all,
I have windows 2k professional with SP3 installed in it ,it is a workstation and not connected to any domain .Recently i created a profile with admin rights and all is going well ,then i changed the virtual memory to the max and still it isworking fine with my user account .Then one day when i restarted the Computer and entered the useraccount ,i get the following error message
“Windows cannot load the user’s profile but has logged you on with the default profile for the system”,reason saying that there is no enough space and it lets me in .
I have no idea what this error is ,what is the problem with this .This problem doesnt come when i enter the with some other account .
Can you tell how to overcome this ,what could be the reason .I have searched the net but not able to get any correct answer .
plz help