Updating OEM W8.1 to 8.1Pro

I have an Acer laptop running W8.1 64 OEM. It has suffered some file damage and needs to be refreshed but the Acer system refuses to work. So I want to update it to W8.1 Pro 64 with a valid Product Key (I already have an ISO and Key) but without losing all the installed applications. Is this possible and if so, how. Thanks for all the help

go into Control Panel and choose Add Windows 8.1 Features..
Select I already have Key..
Type in the Pro Key > windows will update from Home to Pro...
After the system reboots > you can run the Setup.exe from the PRO installation Media from within your current OS

That will refresh your current Pro OS and it will keep your files, setting and programs..

Tried that!

That was the first thing I tried, but it didn't work. There was no useful information in the error message, all it said was 'can't complete - rolling back'! I suspect that the problem might be the way the OEM version has been 'adjusted' to the way Acer want it.

Is there a way of inserting the DVD and upgrading from that?

oem and retail same windows versions - just different licensing policies.

Boot from setup media and do a clean installation of Pro...

You will lose everything, though..

But the content and some settings are particular to the OEM supplier. Only the core elements are the same.

I want to avoid a complete re-install if possible as I don't want to have to re-install critical applications. That's why I asked the question in the way I did.

Keep us posted...

Did you create any recovery media? If yes use that to restore the factory OEM install, then upgrade to Pro. If no, press what ever key is required during boot up to do the factory recovery, and hope it works. Backup what you don't want to lose beforehand though. It will erase everything and put it back to the OOBE, Out Of the Box Experience.