suggest best UPS for 400W ATX cabinet

[suresh_ktnv]

Hi
I have haken a PC in Dec'06. My PC cabinet is ATX 400W and I am using 17" CRT monitor of Samsung made. I purchased Numeric Company UPS 600VA.
It will not withstand even 5 minutes when power failure. Please suggest the corret rating of UPS for my PC.

 

[Alphatronix]

This one should be fine. Im suprised the 600 gives your problems.

http://www.newegg.com/Product/Product.asp?Item=N82E16817152022