Log-in problem

[Nervous SLF]

On my wifes 2 year old ACER laptop when she goes to log-in to her Hotmail, Facebook, Amazon and other websites, it asks for her log-in name and password even though she has ticked the remember me box.Sometimes this happens after only a couple of hours, a couple of days and sometimes after a couple of weeks. Also it frequently logs out whilst she is actually on the selected webpage and she has to log-in all over again.She had a snag with her first Hotmail account so she opened a new one with new password but sometimes when she goes to log-in it puts her into her original Hotmail account not the new one.

Any advice is very welcome, even if it is to dump it and buy a new one.

[vulcanised]

Not accepting cookies when you need to is the first thing that comes to mind.

[Milo Minderbinder]

or maybe more likely.....a security settings change which is clearing out cookies.

Has the antivirus software been changed?
Has anyone changed privacy or security settings in the browser (which browser? IE or Firefox or ???)
Is anyone using a clean up tool like CCleaner?

any of these could cause it