I'm about to make backups of all my data to I guess one HDD.  Do I have to set the security to public or something so that when I rebuild my PC with a new clean install of Windows 7 I'm not going to have problems with being able to access the files (especially if I use a different user name? - does this matter??). 

I could do a Microsoft Backup do a HDD and probably would do just some straight copies of folders (Pictures, Music & other files).  Will MS Backup then have a problem with restoring?  May be safer to do just straight copies?

It's just I remember some problems with not being able to delete some folders when I did something similar way back.

Any tips or help appreciated.