It's possible that you may not have the jumpers set properly on the hard drive you installed into the laptop. However, assuming the jumpers are correct here are some things you can try.
1. If the CD drive is removable on the laptop (with a simple switch on the outside of the laptop). Try removing it and see if dip switches or jumpers can be set on the back of the drive. Not all laptops have this ability, however if available something that can be easily checked.
Jumper info:
http://www.computerhope.com/jargon/j/jumper.htmAlso likely it's not a jumper on the back of the CD-ROM but a dip switch. Dip switch info:
http://www.computerhope.com/jargon/d/dipswitc.htm2. Boot the computer into CMOS, in CMOS see if the CD-ROM is being detected, the CD-ROM should be shown as the secondary drive or one of the drives listed. Unfortunately can't give too many details about where this is since all CMOS screens are different.
Additional information about entering CMOS setup:
http://www.computerhope.com/issues/ch000192.htmIf not detected in CMOS then it's likely a hardware issue (e.g. jumpers on hard drive not set or when hard drive was installed something was disconnected causing the CD-ROM not to work).
If however the CD-ROM is being detected it's likely a Windows XP related issue. Try removing the all CD-ROM drives and other devices from device manager. Reboot the computer and Windows should be able to detect and setup the drive for you.
