I have a xp home ed desktop. I was having a few problems with a network so i decided to do a system restore.
Once it had completed, and powered back up again. i found that i didnt have any adminstrator privilages even though i was logged on as the computers administrator. (administrator is the only account on the machine).
I cant access user accounts restore, install or uninstall aps pritty much cant do anything.
Try starting in safe mode and selecting the "Administrator" account (Not your own login name) Then access your user account from Control Panel and check the settings there. If necessary set up a new User Account with administrator priviledges and see if that one works OK when you boot back normally.
Can you access 'user accounts' by going to Start > Run and typing in 'control userpasswords2' (without the quote marks) and clicking OK? If you can, try setting your account to Administrator in there by clicking on your account and choosing Properties. Under the Group Membership tab, tick 'Other' and choose 'Administrators' from the dropdown list.