The clock on the GX240 is not an atomic clock.

You cannot be guaranteed of a good battery unless you buy new.

Clean battery contacts are required.

If it retains cmos settings then the battery is working.

If it loses them and says cmos setup invalid the battery is bad.

If you BENT the contacts too much getting the old one out the new battery will not work.

I was pretty careful when I took it out so I hope I didnt ben anything. when I restarted the pc it did say time/date were not set.

Thanx

If you set a date and time then turned off and it still says the same then the battery is bad or the socket is BENT or broken. Usually attempts to fix this cause the bent pin to BREAK off.