Windows Vista XP Photoshop CS3 files being locked in Vista

I have psd files created in CS3 with the XP Home, saved to an external hard drive, then imported onto the new Vista Home Prem.. The files are avialable to be worked on but Vista won't save any changes... " could not save the file is locked... use the Properties command in win expl to unlock the file." I've spent hrs trying to "unlock" the files and still no success. Its a large portfolio and I'm hoping that someone has a solution. Thank you very much for any help! Mike

 

Locked Photoshop CS3 files in Vista

Arie,
Thanks so much for the reply. The key bit of info that neither I nor anyone, including Adobe, had was the Read Only Attribute. They were all marked read only. Changing this seems to be the solution. Your help has been immeasurable Arie and I am deeply thankful ! Best Wishes to you. Mike