Windows 2000 and XP both have specific "permissions" requirements when working with various files and registry entries. Windows "locks" them and there may be different ways to solve the problem. Your "hunt and peck" method is frequently the only way to get it done. First, in order to change system files, you'll need to be logged in as a user which has "administrator" priviledges. That usually gets things done. Occasionally, you'll need to log in as the "Administrator" username which is the original user ID from the computer.

The error messages you're seeing {"cannot read from source file" and "(file) access denied"} may have different causes. With "Access Denied", it might be a "read only" file attribute that needs to be changed. If that's not it, I find it easiest to attempt file removals in "Safe Mode" but even then, you may not be able to uninstall a complete program that uses the "Windows Installer". In those cases, the uninstall must be done in "normal" Windows. "Usually", Safe Mode frees up some of those locked files and allows for deletion. Sometimes other means are required such as the Recovery Console or using a third party program like "MoveOnBoot".

As with most computer problems, use what works.

Hope this helps.