My computer take long time to open

Possible that PC is hanging up as there is fault on the OS (operating system) or a virus in the OS. Also it is possible that the backup battery (CMOS) has low voltage or the memory card is a suspect. In this case you need to check the voltage and also try and swap a memory card. Sometimes the memory card connections can be faulty either on the card or on the slot. Cleaning the slot and card must be done before you try a replacement. If the PC boots and fails then the hard disc can have bad sectors or is corrupt. However if there is no result the motherboard also can be suspected. In this case you might need the help of proper tools and equipment support to do a chip level service.

It is best to go for a paid antivirus software which you can get in a package. Personally we are not recommending any particular company but you can try with Avira, Antivir, AVG, Kaspersky. It is always best to install the antivirus when the installation of the OS is done.

Now before this you can open the internet options in the browser and clean all the cookies, temporary internet files, defragment the drives and RESTORE the PC to an earlier set date.

You can use a registry cleaner like Advanced system care. Download from the site and check you system for corrupt files. Also use a good antivirus software which is active to keep your system performing without an attack on the OS. Remove all unnecessary programs installed which you do not use all the time and clean up the drives. This will free up the space and make your system faster.
If there is no response but the PC tends to work slower and occasionally hanging when a program is being executed then you might have to install the OS once again. Install the OS and then an antivirus before the drivers of the PC is installed.