New member needing help

I made was about to buy a new pc through finance when for some reason i was declined? my credit score is fine money is fine bank details are fine? i dont know what to do!

Is it possible you didn't meet one of the criteria set out by the finance company?
They are:
1. Be 18 years of age or older.
2. Be in permanent paid employment (over 16 hours per week), retired and receiving a pension or self-employed.
3. Be a UK resident (minimum 12 months) and intend to remain resident in the UK.
As stated here: https://www.pcspecialist.co.uk/finance/
And it does say 'Our finance company does not provide a reason for declining applications', so unless you can find a mistake in your details in your application (which might explain why it was declined) I wouldn't expect to find out why it was declined

If you don’t enter the right addresses as per your credit history, not your actual previous addresses can be a reason. Could be anything really.

Unfortunately PCS don't do the finance themselves and it will have been the finance company who declined your application. Sadly there is thus nothing that PCS can do to help really, it's up to the finance company, they're the ones lending you the money. You might try checking your credit score with several agencies, they do vary sometimes....

You could always try one of the free credit reference agencies (i.e. noddle) to make sure your personal information they hold is correct and up to date.

It might also be worth asking the finance company which credit reference agencies they used so that you can check that what they hold about you is correct and up to date.