windows PE

i'm a beginner to windows 7.
i want to know if windows PE is automatically installed when we install windows 7 from a DVD disc . OR it is installed separately ?
to explain more : the tool called windows PE that helps to recover a failing system - that we found in PCs sold with included operating systems-.
sorry for this bad language . and thanks in advance

Yes, windows recovery environment (RE) is automatically installed on the local hard disk as part of windows setup. You need to press F8 repeatedly at boot till you see the Advanced boot menu. Then use the arrow keys to highlight Repair your computer and hit enter.

The OEM manufacturer's Recovery Partition & System Reserved partition are not the same things.

To make the System Reserved partition yourself take look at those tutorials:
SSD / HDD : Optimize for Windows Reinstallation
System Reserved : Create Using Disk Management

To have windows PE on a CD,take look at this tutorials:
System Repair Disc - Create

thank you for your help