Admin rights loss
I run Windows XP sp2 on a T42, an old company laptop I was given when I left a company. I was overzealous in wanting to clean up my drive. I used ERASER and obviously erased a bunch of files I shouldn't have. Bottom line is that many of my settings are gone. Prior to using ERASER I had downloaded and used CCleaner, Advance Windows Care V2, iObit defrag, nCleaner, Recuva, and Undelete Plus. I used Recuva to identify (or I thought) files that I wanted to delete, I used ERASER to erase them all. Since then I can no longer use any of the freeware downloaded (except CCleaner). The message is always the same: I do not have Administrator's rights to use the program. It is the same with many tasks like checking the User Accounts (it defaults to the Administrator username and is asking for the password that of course I don't have). I am not able to download any more software from majorgeeks. Every time I open IE it takes me to the "new settings" page. I set it up but it doesn't save anything apparently.
I am a little bit at a loss and don't know where to go next. I do not have a backup of my system. I have tried the system restore to go back to a previous check point but it won't let me do that either. It won't let me use PC Doctor (because of lack of admin rights).
I have read a lot on this site and it seems like I need to fix the admin rights problem before I will be able to do anything else (malware problem after that). I have seen recommendations for using ERD commander. Is this the thing to do at this point? (if it is where can I find it and how difficult is it to use?). I do no longer have an antivirus, tried to download AVG but download doesn't work.
Anyway, any help, if still possible will be appreciated.