RE: Registry cleaners-good or bad?
Unless the documentation for the BIOS update indicates it will resolve a problem you are having, do not do it. There is a small but real chance that the update could brick the computer. For the network driver update, check to see if it will be helpful. There are very few reasons to do any driver updates. NEVER use driver update scanning programs to identify updates. You do not know if the updates it will install are safe. Always use official Dell updates.
You rarely NEED to use registry clean-up programs, as registry updates will not really slow the machine down. Having said this, however, I routinely use both free Advanced System Care and Wise Care 360 to clean up everything in mine, including the registry. I have never had a problem with either over many years. I used to use CCleaner way back, also with no problems.
XPS M1530, Win 10 CU Pro 32-bit
Inspiron E1705, Win 10 CU Pro 32-bit
Dimension 9100, Win 10 AU Pro 32 bit
Inspiron 660, Win 10 CU 64 bit
Inspiron 3668, Win 10 CU 64 bit
Asus T100 Tablet, Windows 10 CU 32 bit