As per my opinion, this is not logical to convert DHPLC to simple HPLC. Because, DHPLC is an advance version and can be used for DNA analysis (forensic applications) which is difficult with ordinary HPLC method.

It depends on the equipment manufacturer, if the equipment has modular parts like a separate pump, autosampler, column oven and UV detector then it should be possible to convert a denaturing HPLC to a regular HPLC. As I understand it, the major difference between the 2 types of chromatographic systems is that the denaturing HPLC has both the gradient mixer, and sample injection valve inside the column oven. Our new Shimadzu Nexera system has the gradient mixer in the column oven compartment but not the sample injection valve (separate autosampler), although there is plenty of room in the column oven for a manual injector valve. This should not make much difference as far as HPLC is concerned unless your samples are unstable to the higher temperature in the column oven. The denaturing HPLC also uses a specific column for separating the DNA fragments, unless some type of non-standard tubing and fittings are being used, it should be possible to swap out the column for regular HPLC column.

If the system is an all-in-one with integrated pump, autosampler, column oven, and detector your chances of converting the system over to a regular HPLC system will be diminished. The pump may be a limiting factor because it was optimized to the flow (and pressure) of a single type of column and can not be easily used at any other flow rates. The UV detector may be limited to just a few wavelengths and may not be adjustable to others required for general HPLC. The controlling software may also not allow for the other parameters you would want to adjust for general HPLC experiments. If the column oven is built around the column you may be limited to the column format (length and diameter) that you can use inside the oven.