Restore my windows xp to original configuration
When I try to open icons on the dsktop what appears is a Chechsum dialocue box. To open any icon on the desktop, I have to right click and the Checksum box appears where I have to choose the option to open. Another of my problem is I cannot open downloaded files from the Internet. I would like to revert to the original system when I boot this computer. The files are downloaded but the problem is in opening them. There are several options for opening the software but none of them seems to work Can you help me with these problems?