I am getting error 800 freqently, please let me know if there is any direct solution for this error.
No 'direct solution'.
There are MANY reasons for status 800.
Start by posting all text in Job details of failed job.
PS: You have selected NBU 7.5 and Windows 8?
I doubt that is actual NBU version and OS. Please share exact details.
Supporting Storage Foundation and VCS on Unix and Windows as well as NetBackup on Unix and Windows
Handy NBU Links
Normally it occurs, when NBJM stops responding.
So recycle of services may resolve the issue.
NBU Process flow : https://www-secure.symantec.com/connect/downloads/netbackup-7x-process-flow<