Will long-term use of ubuntu via wubi harm my PC?

No, using Wubi or extended periods of time will not shorten the life span of your computer at all.

However, there are many advantages to dual booting as opposed to using Wubi. For example:

• Wubi is slower then a dual booted Ubuntu install, and Wubi installs cannot Hibernate (it can Suspend).
• Wubi installs are also much more likely to break through an update.
• Dual booting the computer does not endanger Windows 7 at all, and the Ubuntu installer makes dual booting very easy.

I would highly recommend dual booting if you intend on using Ubuntu for long periods of time.

If you currently do not have problems with your Wubi installation I do not see how it could harm your PC.

There are a few things to consider though (in theory):

• If you have heating problems under Ubuntu, that can shorten the lifetime of your hardware components.
• By using NTFS partitions to exchange data between Ubuntu and Windows there is a slight chance to somehow break the integrity of the Windows filesystem. Or if it is your Windows system partition, you could modify it so that it will not boot.

It is always a good idea to have a separate Ubuntu installation, because if the other OS might fail, you can access your data from the working one.