Windows 7: have installed win 7 , but windows xp has taken over

hi all, I first installed windows 7 on the partitioned hdd, then I loaded win xp on the other part of the partition , now it only loads win xp .
I want to have the option to boot to win 7 also on the splash screen .
cheers

You installed them in the wrong order, you should have installed the older OS first. XP then windows 7. Windows 7 would have detected XP and set up the dual boot menu for you. XP likely couldn't ID the newer OS and overwrote your boot loader leaving out Windows 7.
Dual Boot Installation with Windows 7 and XP
There are some other Related tutorials at the bottom of the page that may help you sort it out.

If you don't want to reinstall both then start Windows 7 by marking it Active then running Startup Repair - Run 3 Separate Times from Windows 7 installer System Recovery Options.
Partition - Mark as Active (Method Two)

Then install EasyBCD (free Download at bottom of page - no name or email required) to add XP using Add OS Entry tab.

You can just download and install Visual BCD package.

Run "Dual-boot Repair", click on "Automatic Repair" and confirm.
Reboot.
Windows 7 should start.

To add boot entry for XP from Windows 7 run Visual BCD Editor:
right-click in left pane, select "Create missing Windows loaders" and confirm.

That's all.

To rename a loader entry -> select loader, type F2 key (or select "Rename" from popup menu) and change text.

Boyans, I see you wrote Visual BCD editor. Can it be made to configure a Dual/Multi Boot from XP when it has been installed second and stolen the boot from Windows 7?

In the current configuration yes.
Windows booting as we all know is dependend from active partition.

When installing XP it places its boot files on active.
"Dual-boot repair" adds/repairs Windows 7 boot files to active.

The automatic addition of XP related BCD entries creates a complete Windows 7 dual-boot.

The other case around involves inspection of active and copying of XP boot files if missing - but usually Windows 7 installation when XP present does this.

gregrocker,
A more general scenario of having several XP installations and several Windows 7 installations is not handled by Visual BCD but is in development.

The problem is that you have to put all XP installations in BCD and also in boot.ini.
Adding all Windows 7/Vista/XP to BCD is handled by VisualBCD (automatically on click).

I am not sure that any current tool can handle a general scenario automatically - what do you think ?

The only process I bother with any longer when XP steals the boot is repairing Windows 7 to boot so that EasyBCD can be installed to add the other OS's.

I've had no problem adding any other OS's including Win8 after this, although Win8 will give an improved Metro-style Boot manager if it is correctly installed last to configure the boot.

We've handled countless numbers of these without ever having to actually edit the BCD thanks to EasyBCD. However it has it's weaknesses. Using Easy to move the System boot files to another partition loses the F8 System Recovery Options which consumers don't want to do, so it's best to stick with running Startup Repair - Run 3 Separate Times after marking the target partition active.

And I won't mess at all with trying to add other OS's from XP using Easy because it increasingly fouls out and if pushed can corrupt it from being added once Windows 7 is restarted. Can you fix that?