no operating system upon boot

I may be too late but... Have sony vaio laptop with XP home. Had drive
partitioned to a c primary and d extended. Ran into issues as the c drive
was full and nothing was going to d. Went into drive management and
formatted d drive, as only data stored there was copies of program files
that also existed in c drive. Upon attmpt to make it merge back with c
drive, formatted it to also be primary drive. Didn't touch c drive, but
upon restart laptop only displays one message: operating system not found.

I have Sony recovery disks but they simply prompt me to totally reformat and
start installation of system. Have I lost my data and is there any way to
get the laptop to boot correctly to for now at least get back to where I was
before the issues?