how to access my wallet.dat I setup a Bitcoin many years ago. I dont remember if I bought anything.
I found on my old computer a folder : Bitcoin under Appdata/Roaming ...and these files and Folders:
 BLocks
 Chainstate 
.Lock
dblog
debug.log
peers.dat
wallet.dat

Was those files installed my a program of some sort ?
How can I get Access to those files to see if there are some coins in there at all ?:)
Or can I just delete all of those files ?

-
Those files are created by Bitcoin Core software. The important one is wallet.dat, do not delete it. You can download and run bitcoin core to open the wallet, but that will probably take a long time to sync. You could open it and dumpwallet, and then check each address on a block explorer or import them into a different wallet like electrum