The given equation is:
\[
\log_x x - \log_{10} \sqrt{x} = 2 \log_{10} 10
\]
Using the logarithmic properties:
\[
\log_x x = 1 \quad \text{and} \quad \log_{10} \sqrt{x} = \frac{1}{2} \log_{10} x
\]
Substitute into the equation:
\[
1 - \frac{1}{2} \log_{10} x = 2 \times 1
\]
Simplifying:
\[
1 - \frac{1}{2} \log_{10} x = 2
\]
\[
\frac{1}{2} \log_{10} x = -1
\]
\[
\log_{10} x = -2
\]
Thus, $x = 10^{-2} = 100$.
Thus, the correct value of $x$ is 100.