Have toshiba note book,windows vista opens only in

It may well be some form of virus or spyware.

It may also be that you have too many applications running at once eg. lots of toolbars and instant message typ programs.

It can also happen on graphic intensive applications.

You should rule out nasty stuff first.

MBAM !

for a free one its pretty darned good !

From a CLEAN computer download and put on a flash drive.

Copy to your DESKTOP on the suspec computer.

Run it but dont change any options just use what it offers.

When its done let it clean anything it finds.

Its where I always start with an infected machine.

As for antivirus AVOID Norton or Mcafee but try the AVG FREE version MBAM should clean up without buying

Only continued use would require purchase As for too many applications that would be up to you to decide what you REALLY need and dont. Most toolbars are a waste of both time and space and can hog computers down. Maybe a good clean up is in order ?

It may just be a "leaking application"

These are badly coded programs that dont release memory when they should and just keep taking more to do the same job.

May I suggest you download "hijackthis"

It is a program that can make a report on what you have running in such a way that you can post that information to certain sites and experts there will look at it.

They will then give you reccomendations as to how you can remove programs or fix some issues that may be upsetting your computer.

Dont post the log here but follow the nstructions and help the program offers to send it to one of the sites it will offer you.

If you understand startup lists you may even be able to spot som things yourself that you dont want to run and disable them from hijack this.
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you have a software conflict or a virus you must try a system restore to a preveous date or try to remove conflict in safe mode hope this helps.Install a new antivirus software. Last and i know you dont want to hear this but you may have to reinstall windows on a reformatted hard drive losing all you data.this is worse case.