You know what. Your lilo.conf has all the solutions. You don't need us. Just remove the # in map-drive statements to like this
# Windows bootable partition config begins
other = /dev/sda1
label = Windows
map-drive = 0x80
to = 0x81
map-drive = 0x81
to = 0x80
table = /dev/sda
I only marked the lines I changed in red
(just removing the # to enable the lines)
Save the file and type
to recomiple Lilo
Explanation if you are interested.
Your Windows was booted as the first boot disk sda but now the Linux hda is the first boot disk. Windows gets jealuos and doesn't play ball.
If you re-map the disk order at the time you boot Windows, tell the bugger it is in No 1 position then the sucker will buy it. 0x80 is disk No. 1 and 0x81 is disk No.2. It is a temporary arrangement and the disk order reverts back to the original as states in the Bios as soon as Windows exits.