I have just started using an old computer of mine for video editing with In-sync Speed Razor and a Fast DV Master Pro capture card.
My problem is that when a browser is opened, ie. for changing Speed Razor directories or for installing drivers, the only drive that is seen is C. The drives window in the browser only has C listed or is completely empty.
I hope someone out there can help.

Sounds like this old computer is broke. At least for floppy and cd drives.

Start by going into Disk Administrator and see if they are listed and if so what their assigned drive letters are.

When booting up do the lights blink on the cdrom/a: drive? Maybe a cable has come loose or the power disconnected.

Last but not least look at Event Viewer for errors that may provide a clue.

Disk admin and event viewer can be found via Help.

Give a person a fish, they eat for a day. Suggest they internet search and they learn a skill for a lifetime.

Thank you for your reply.
I forgot to mention that I have 2 x SCSI, 2 x IDE, 1 x SCSI cd-r and 1 x floppy in total.
All of them are in Disk Admin, Explorer, My Computer etc. and I can work with them as normal. It is only when a browser is opened ie. when installing drivers etc. that the drives are not seen.
You are right about Event Viewer. This is what it reports:
Source - i8042prt Category - None Event 35 User - N/A.
Does this mean something to you? I feel I am getting closer to the source of the problem.

I have just realised that this event does not match up timewise with me opening a browser, so it must be for something else?!?
Not crucial because I have not noticed anything untoward happening.
The main problem is that in Speed Razor I cannot choose drives to save files to. Hope you can help.

Speed Razor looks to be a pretty old program [1998?]

If you can see the drives in My Computer and Explorer then its the app that has the problem.

Sorry can't help you there.

Give a person a fish, they eat for a day. Suggest they internet search and they learn a skill for a lifetime.

Yes it is old, but even when Razor/DV Master is not installed the browsers do not show anything other than C drive. The workaround is to copy and paste drivers from the original disk to a temp folder on C. I presume that others that have an NT4 system do not have this problem, although I haven't got another NT machine to compare it with.