This is not a SQL Developer issue. You will get much better advice in the Database - General forum.
In the absence of a proper backup, your options are limited. There are ways of recreating the database but they are highly technical and dependent on your having all the required files, not just the data files.
>also installed OracleXE112 on the laptop
Likely you also created a new database and have the database instance up and running.
You need to shutdown this database before you can overwrite it.
We will assume that the "old" database had been properly shutdown before the read/write errors.
You will need the controlfile and the database files of the "old" database. You may need archivelogs / redo logs depending on how your database was shutdown.
Hemant K Chitale
Hemant, my old drive (k drive now) has around 21 gb of data within the following area:
with the files
So I thought I could copy these files and replace the same files I have on my c drive, but its not as simple as that lol.
I have from cmd, connected to rman on the k drive but when I try and connect to the target database I get the following error:
ORA-12154: TNS:could not resolve the connect identifier specified
I dont no if its reading the tnsname.ora from the c drive or the one from the k drive...
You are trying to connect to an instance that hasn't registered with the listener yet.
If you have these files on C: that means that a databse instance was created when you installed XE. You need to have the database instance in MOUNT but not OPEN mode.
Also, don't try to connect through a network connect string with RMAN. (I wonder if XE is configured to allow a local connection using ORACLE_SID)
Hemant K Chitale