There are many things that could be causing the problems that you are seeing. It could be low disk space, a damaged drive, Outlook causing heavy disk access making the system sluggish (2GB is quite a substantial amount of data for it to deal with), or it could even be a malware infection.
The first thing to do would be to clean out any old and unwanted data using some software such as CCleaner or IOBit Advanced SystemCare, both of which may be able to free up enough space for Outlook to work properly and SystemCare may also potentially fix other related problems.
Next I would run a full disk scan in order to identify potential defects with the disk. From How to run Chkdsk from My Computer or from Windows Explorer I would scan for defects on the disk, as detailed below. Note that this may take quite a while on large drives.
- Double-click My Computer, and then right-click the hard disk that you want to check.
- Click Properties, and then click Tools.
- Under Error-checking, click Check Now. A dialog box that shows the Check disk options is displayed,
- Use one of the following procedures:
- To run Chkdsk in read-only mode, click Start.
- To repair errors without scanning the volume for bad sectors, select the Automatically fix file system errors check box, and then click Start.
- To repair errors, locate bad sectors, and recover readable information, select the Scan for and attempt recovery of bad sectors check box, and then click Start.
Note If one or more of the files on the hard disk are open, you will receive the following message:
- The disk check could not be performed because the disk check utility needs exclusive access to some Windows files on the disk. These files can be accessed by restarting Windows. Do you want to schedule the disk check to occur the next time you restart the computer?
- Click Yes to schedule the disk check, and then restart your computer to start the disk check.
You also state you are using Kaspersky 6, that product was End-of-life'd back in 2008 and you may want to look into updating to something a bit more modern as your first option, as it is probably not providing any real protection against current threats. I've detailed a few options below.
End of Life
Supported until: 2008 Sep 01
Database updates supported until: 2009 Sep 01
Latest version number: 220.127.116.111
Given the age of you machine and prevalence of malware of all forms on the internet I would look at updating to any of the free alternatives such as Microsoft Security Essentials, AVG Free, Avast or any other of the free alternatives.
I would also recommend running Malwarebytes Antimalware (the free version) to see if there is anything else that might be causing a problem.