When you reboot your computer, at the very beginning of the boot process, start pressing F8 regulary.

You will then get a black screen with options like Safe Mode, Safe Mode with Command Prompt, Safe Mode with Networking, as well as other options.

Choose one of the Safe Mode options, and the boot process will continue, ending up with the computer booted in Safe Mode.

You can then uninstall your product from here, either using the vendor’s Uninstall Utility, or through Windows.