You have a '98/XP dual-boot; you want/need/are considering to re-install '98...; will XP still work afterwards...(Bear in mind that the XP boot/start-up files reside in the active Primary partition; as do those for ’98.)
The answer is no...; regardless of where it (XP) is currently installed. However it can be made to again relatively simply.
Presuming '98 is in c: ..., and you decide to reformat c: in the ’98 re-install process, then you will lose access to XP - as you will delete the XP boot/start-up files when you reformat c: . If you do not reformat c: you will still lose access to XP – temporarily.
If '98 is elsewhere and XP is in c: then again you will (temporarily) lose access to XP following the re-install of '98, even though you would do not do anything to the c: partition in this latter situation…
First: copy the ntldr, ntdetect.com, boot.ini - and critically - the bootsect.dos files to a floppy (presuming you have a floppy drive in this system). Lock the floppy - keep safe, handy; you may need it later, depending on where '98 is currently installed....
Then proceed with '98 re-installation. When you boot up you will have access only to ‘98…
In the '98 re-installation process you will rewritten the mbr from the XP version to the dos/'9x version; thus disabling access to XP.
Now… if you “did” reformat c: then you will need to copy back the contents of the floppy you made earlier to the c: root of the drive (where those files resided originally). (If you did NOT reformat c: then there is no need of copying those files back; but you could anyway…)
Then run XP setup/repair routine (CD boot) and use the fixmbr option. Once complete you will (all things being equal) have access to XP – and thus your dual–boot - again.
The critical file in this whole operation is the bootsect.dos…; this file (created by XP) is needed to allow ’98 to boot via the XP boot-loader; and without it ’98 will not boot from within the XP boot-loader environment…. If it is lost in the above exercise then you have to recreate it. This can be cone manually (you write it… - details at Doug Knox site and other similar sites) or you allow XP to (re)create it for you. However, by saving the current copy first (off the system), you can avoid the whole issue, as you can simply re-install the original (if needs-be) after you re-install ’98. This approach does require you re-install ’98 to its present location; otherwise the bootsect.dos may not be correct…; but I doubt you will re-install ’98 elsewhere…?
You don’t elaborate on the exact errors/issues you’re having with ’98 at present…; possibly folks here with more savvy re’ 98 might be able to suggest resolutions that do not demand a re-install of ’98? Regardless, which way you go about re-installing ’98 (should it be necessary) depends on your own preferences. Some will advocate a total clear out of current version; then re-install afresh. Some will suggest an over-write of current version; i.e. re-install to the same folder as present. I can see benefits to both approaches; but a fresh/clean install may be better? All a matter or preference?
A but detailed perhaps... but I feel it's useful to understand the whow/why etc. of a rebuilding a dual-boot... The possible pitfalls can be avoided with a little planning etc...
