Uninstall any previous version of HamTimer before you install a newer version.
A new file format has been incorporated with HamTimer 3.
After you download HamTimer 3, you will need to visit http://www.7-zip.org/

Step 1: Download HamTimer
Step 2: Download the 7-Zip Archiver utility for your system. Don't worry. It is COMPLETELY SAFE and FREE.
Step 3: Install the 7-Zip utility. It is best to right-click on the installer, and choose Run as administrator, otherwise just double-click on it.
Step 4: Using Windows Explorer, navigate to the folder that you have downloaded HamTimer to. 
Step 5: Right-click on the HamTimer package file. In the popup menu, go to: 7-Zip > Extract here. This will create a folder called "DISK1".
Step 6: Open the new DISK1 folder.
Step 7: Right-click on setup.exe and choose: Run as administrator. Follow the prompts.