Tape Drives

HI

I want to know what is the latest IBM drivers for tape drives that supports windows 2008R2.
I've got a problem when I reboot my backup server.
the drives swop around all the time, I dont have any tape drive software installed on the new NetWorker server although we did have drivers installed on our old windows 2003 backup server.
The tape drives were working fine for months now, without giving problems, we could reboot the server and nothing would go wrong.
Until recently we constantly faced with this problem, where our drives serial numbers are swopt around...then we have to delete the library and re-configure the devices again using jbconfig.
We have 4 drives shared to storage nodes and 2 drives are non-shared.
I want to get my devices back to the way they were.
this is what it looks like now:
\\.\Tape0 - SN001
\\.\Tape1 - SN007
\\.\Tape2 - SN019  -non shared
\\.\Tape3 - SN01F  -non shared
\\.\Tape4 - SN00D
\\.\Tape5 - SN013

this is what it looked like before and I want to get it back this way again:
\\.\Tape0 - SN001
\\.\Tape1 - SN007
\\.\Tape2 - SN00D
\\.\Tape3 - SN013
\\.\Tape4 - SN019 -non shared
\\.\Tape5 - SN01F -non shared

can you please tell me how I can get my drives back to the order they were before ?
How can i move the SN019 and SN01F back to Tape 4 and 5 ?

Thanks