Dear Martha: In shopping around for new windows, I was wondering: Will any of them help prevent my furniture from fading?

A: Most window units consist of multiple panes of glass filled with an invisible insulating gas. Manufacturers also offer windows with low-emissivity (or low-E) coatings, which help block out solar heat. Low-E glass was developed with energy efficiency in mind, although it also offers some fade protection.

There's a relatively new product called ClimaGuard SPF that is specifically designed to prevent fading. When applied to glass, the organic coating is said to absorb 99.9 percent of the sun's ultraviolet rays. ClimaGuard SPF is always paired with a low-E coating, resulting in windows that should minimize fading and reduce energy bills.

If you are not in the market for new windows, you still have options. You can apply ultraviolet-resistant plastic film to existing window panes. You can also hang solar shades, which let sunlight through but block ultraviolet rays.

Remember that other environmental factors, including temperature, wear and humidity, also contribute to fading, so you will need to address those, too.

Dear Martha: Is there any way to get the musty smell out of old cabinets?

A: Try placing a glass or ceramic dish filled with plain white vinegar in your cabinet and leaving it there overnight, or until the smell vanishes.

A more aggressive approach would be to wipe the insides of the cabinets with a solution of one part vinegar and one part hot water. Then you can help prevent the smell's return by keeping a sachet of dried, fragrant flowers inside the cabinets.

Dear Martha: How does Parmigiano- Reggiano differ from Pecorino Romano?

A: The primary difference between these Italian hard cheeses is that Parmigiano-Reggiano uses cow's milk, while Pecorino Romano is made from sheep's milk.

Other countries produce versions of Parmesan and Romano using similar techniques, but they cannot be labeled Parmigiano-Reggiano or Pecorino Romano. Cheese connoisseurs prefer the Italian originals, much the way Champagne buffs choose real bubbly over sparkling wine.

Pecorino Romano cheese is aged for less time than Parmigiano-Reggiano. The former is sometimes referred to as "the people's cheese," because, on average, it costs several dollars less per pound.

With its crystalline texture and rich, nutty flavor, Parmigiano-Reggiano is the more versatile of the two. It can stand alone on a cheese plate, and it's best for adding complexity to dishes, whether a risotto or an arugula salad. Salty, pungent Pecorino is too dry and crumbly to eat on its own, but it is delicious as a finishing element in cooking, as the final layer on a brick-oven pizza, for example, or grated over a bowl of pasta.

Whichever cheese you choose, always purchase it by the block, and freshly grate or shave it as needed. *

Questions should be addressed to Ask Martha, care of Letters Department, Martha Stewart Living, 11 W. 42nd Street, New York, N.Y. 10036. Questions may also be sent by electronic mail to: mslletters@marthastewart.com. Please include your name, address and daytime telephone number.