Reasons for moving your My Documents folder

There are two serious reasons to do this with immediate effect.

1. Imagine that all your precious documents, photos and sundry other files are organized beautifully in this folder on the system partition (commonly the C Drive). Imagine a system crash. Imagine the loss of never able to recover that data. And now imagine a simple step which could have saved the day.
2. The usual good word is to partition your hard disk into multiples with a minimum size kept for the system drive. With time My Documents will fatten up as more data is stashed away in it. Moving the folder to a different drive saves space and more importantly safeguards it.

How To Move My Documents Folder in Windows XP

1. Right click on the My Documents icon on the desktop.

2.  Click on Move and choose your chosen location for the folder. Move it to a different partition. For instance, I have it on my D Drive.

3. Click Apply and then Ok. A prompt will ask whether you want to move all of the current documents to the new location or not. Choose Yes. All your documents are switched to the new location and it’s all like before except now they are safer from a system crash.

Windows 7 - Moving My Documents

source