invalid error number

check and see if you can run bpcoverage -c clientname from the master. If this works you should be able to backup the client. From the client can you ping the master/media server. Check the clients bp.conf file and make sure the master is in there. SERVER = name.
run telnet clientname bpcd and see if it connects.

Glenda,
Make sure you have correct/complete DNS resolution between the client and master.
Also try nslookup on both the client name and IP address.

Another thing to check is if the client is in a different domain than the master; if it is, the DNS name resolution list on the client will need the master's domain added.

You could also try adding hosts file entries on both ends.

$0.02

uninstall the allpication then reinstall it, follow the promts

Thanks Dennis, already Checked the DNS (reverse lookup and everything-- all doing ok)

I'm thinking if I will reinstall or upgrade the client :(
then windows admin would like to leave the client version to 4.5GA -- it's windows NT4-- would it hurt if I install Netbackup 5.1 Mp6 client..
I dont have lab comp to test if this will break the server or not :(

What do you think guys?

Glenda,
It depends on how up to date your NT4 install is and what version your master server is.
I believe the 5.x client requires a certain SP level (SP6a I think) of NT4, which, of course, requires a certain level of Internet Explorer.
If you're already up to date on all that, then you should be OK with the 5.x client.

Of course, if your master server is 6.0, you'll probably want the 5.x client.
If your master is 5.x, you're also OK with the 4.5 client.
That's all in terms 'official support', of course.

Thanks David