FSX Clean Install

[RaptorF22]

I'm thinking of re-installing FSX clean because I have installed so much gunk into it that it's really slow.
First of all, what are the benefits of doing a clean re-install?
Second, what should I do before doing a clean install(backing up files, etc.)

Thanks!

[SamYeager]

First of all, what are the benefits of doing a clean re-install?

IIRC the first few posts of this give some of the benefits.

Second, what should I do before doing a clean install(backing up files, etc.)

Take a copy of the fsx.cfg file and the rewards file.

[Tomcat5]

Definately copy the main FSX folder as a backup.  You can restore stuff from that, such as some 3rd party planes, or addon scenery.  Unless your sim is crawling, I probably wouldn't re-install.