installations on my windows xp operating system

[Michelle]

I run my computer off of windows xp and anytime I try to install a program it succeeds in saving the file to my desktop, but when I click on the file to install it, it gives me this error message: "Windows cannot access the specified device, path or file. You may not have the appropriate permission to access the item."

I am running it as an Administator, not guest.

Thank you!

[Allan]

1) What is new or different since the last time everything worked properly (ie, new hw, new sw, virus, error, etc)?
2) Please run full system scans with BOTH your installed anti virus app and with MalwareBytes
3) Add "take ownership" to your context menu and we'll see if we need it later (http://www.askvg.com/add-take-ownership-option-in-file-folder-context-menu-in-windows-vista/)