I have report where I ask user to write path to dir of files. This parameter have default value on start, but I want to allow user change it. From moment where he change it parameter wrote by user will be displayed as default on next render time.
Edit: I use Buissnes Inteligence and SQL SERVER 2008r2
I don't think this can be done in SSRS alone.
What you could do would be to write a procedure to produce your report output, which accepts the directory path as a parameter and saves it to a user lookup table, before producing the report data.
You could then use a query on the user table to produce the default value for the parameter in SSRS.