Operating Outlook 2007 on Win 7 Home Premium 64bit system.

I get the error message "...outlook.pst has reached it's maximum file size"... when I try to do anything in outlook.

I would like to delete or move some files but it will not let me do that. Instead it keeps giving me the same message.

I have created a new personal folder and directed new email into that so I can still receive email but I can not send email or delete / move anything in the original Outlook.pst file.

I have read you can make registry changes to increase the pst file limit. I would consider that as a temporary fix so that I can clean things up and then return them to the original setting but registry changes make me nervous and I need direction on how to do that.

Any help is appreciated here. Thanks.