cant boot into windows after installing ubuntu server 9.0.4

view story

http://askubuntu.com – I was installing ubuntu server 9.0.4 on my laptop running on windows seven x64. I install it from cd, and im not very sure about how the partitioning system as shown on the setup. Im not very sure which one i pick and then, after the setup run successfully, i cant boot into windows. And when i put the windows installation disk, it cant even recognize the type of my disk. It even said ita not ntfs file system. My question is, is my data still in there and is there anyway i can retrieve it back? And, does that mean my disk hv been cnverted to ext2 format? Thanks for ur time. Really appreciate (HowTos)