Why is my Dell Latitude 5430 keep showing inaccessible boot device

These Dells defaulted to Intel IRST :-(. If you ever installed Windows XP-7 on these in IRST or AHCI, the setting has to match (Ex: I disabled IRST on my E6540 when I had to reload Windows 7). The issue is you committed to it because XP-7 DID NOT TAKE WELL to the switchover without tools like HBCD to convert it to get rid of the 7B error to the point most people reinstall or commit to IRST or AHCI.

8 and 10 made it easier because you could avoid using tools like legacy Hirens Boot CD to convert it and you could easily convert it by rebuilding the MBR and BCD with these commands:

• bootrec /fixmbr (legacy and UEFI)
• bcdboot C:\Windows (UEFI)
• bootrec /rebuildbcd

BUT for WinXP, it's a pain. You need to reinstall Windows or use a tool with fix_hdc.cmd (Fix Hard Disk Controller), which HBCD 10.6 is known to have - later versions may have removed it as the developer started to remove pirated tools and there were casualties -- it's still in 15.2 so this trick still works without an old non-PE version like 10.6. it will be under Registry tools.

For Windows 7, the same tool for XP is needed if it can't boot into a tool which lets you edit the registry as follows:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\msahci -- Set Start to 0 Set Start to 3 for IDE/ATA
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\IastorV\Start -- Change the Value data to 0 (which means load at boot).
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\pciide -- Set Start to 3 Set Start to 0

As soon as you do that it isn't a guarantee but most of the time it converted it to run on AHCI if you installed on the IRST default. Sometimes it still needed a reinstall as the Hirens trick doesn't work past 7 due to secure boot, but it can fix it in some cases. You can find it here: https://www.hirensbootcd.org/old-version...