Mold on walls

[Eric Tsang]

Hello BiggerPockets,

Every cold season my bedroom walls located where the windows are get moldy all the time. A few questions maybe some experts can help me with -

1. What can i do to prevent mold from building up?

2. Should i replace the insulation and dry wall?

3. Do windows need to be replaced? the edge on the windows are also get moldy every cold season.

Thanks,

Eric