How did you change partitions around or did you remove a Windows primary NTFS partition?
Windows only boots from a primary NTFS partition with the boot flag. Normally all the boot files for additional installs are in that first install and later installs have no boot files. If second install is also a primary partition then it usually can be repaired to add boot files.
But if install is in sda5 that is a logical partition and not easy to boot.
Only with Windows XP can you do some work arounds and make it work, but better to have it in a primary partition sda1 thru sda4. You can also use tools to modify partition layouts to convert a logical to primary but that often depends on exact layout of existing partitions on drive. All logicals have to be together in one extended partition which counts as one of the primary partitions. And then you can only have 3 more primary partitions.