Copying Oracle datafiles to a system clone We have an Oracle 11G R2 on Windows 2008 R2. 

One night, a windows update package caused our Oracle Instance to be down (no way to connect using sqlplus. we believe it's a network, NIC issue.).

We have restored the system from an 36 hours old system snapshot. We do not use archive mode. So every single parameter file in oracle stays same, but datafiles are old.

Question is, can we shut the db off and copy the newer datafiles to the restored system? Is this operation safe?

Thanks in advance.
Of course you can, if you can cleanly shut down your old database and it is consistent. A little reading of the documentation or googele-fu would have helped. Searching this site would have provided this excellent answer. 

But: what do you want to achieve? If it really is an issue with the patch and your hardware configuration, why do you expect your clone to be not affected? 
Is only your SQL*Net communication not possible or does e.g. RDP not work, too?

So before cloning the database without knowing the root cause I would suggest some further investigation and searching MOS. If it really is an MS patch issue that stops SQL*Net from working, there will be almost certainly a note there.

Some peeking in your firewall configuration might help, too, perhaps it is a trivial think like the patch has (re)activated your internal windows firewall.