System Registry Limit

On booting my windows XP professional desktop computer I receive the following modal dialog box [Windows Low on registry space] and the message

" The windows registry has reached its limit for the system part of the registry. All further updates will be ignored "

I have no idea what this means or what to do about it. Can anybody help?

 

Thanks Evan for the information. I have amended my profile so it has my system details as far as I can determine them - thanks for the heads up on that. I will check out the link and see if I can sort the problem. Thanks again.

 

Evan, I tried the simpler solutions suggested by the link and after cleaning up the drive and clearing out all the restore points the problem seemed solved. The next 7 start ups were fault free and I was beginning to think I could post 'resolved'. Then of the last 4 startups twice the low registry warning message has displayed and twice it started normally. So still confused, unfortunately I have to go away on business to Sweden for a week so the other solutions including tweeking the registry will have to wait till my return. I'll update the thread on my return.