Now, there can be problems with the windows system. These problems come from player involvement. Some players may be pushed to the forefront of the role-play due to the circumstances created by the GM or by the player's personal desire to be the center character. Other players may be pushed to secondary characters or guest characters due to the inability of the player to get into their character. There a some ways to deal with these issues.
If a character is in the forefront too much:
* The GM can incapacitate the character or create a story where the character is secondary instead of the lead.
*The GM can allow for "off screen" scenes, which are scenes that players talk about outside of the roleplay which are still cannon.
If a character is a secondary character:
*Talk with player and better define the character's past, present, and future.
*The GM should make a plot that makes that character more important.
*The GM can also allow for the player to create their own storyline.
If the GM does not do this, players will become jealous of each other, and the role-play may fall apart. Thus, solving these problems as soon as they start is important.