Many infection symptoms in my machine-- need help

I am facing many problems in my single machine; this is a Toshiba Tecra laptop, running with windows 7 home premium. The machine was working fine till the last few weeks. Bu suddenly from few weeks it continuously creating some problems regarding different applications, those are applied into my machine. One of them is the browser, Firefox is crashes frequently, for that I need to access internet in internet explorer, which is also responding very slow for each and every operation, freezes few times, while tried to load nay page. It is very hard to start or turn off the machine, for windows explorer not responding. Another problem which I noticed from last night that, there are a several number of instances of "svchost.exe" are running in the task manager, if I tried to stop the execution, the windows explorer stopped working. What should I do now? Is there any one having any solution for this? Any suggestion will be appreciated greatly.

After reading the complete post, I think the cause of all the problem s is must be the operation system, for that I would like o recommend you to reload the operating system, along with this, also you need to install the software’s those are needed for you to urn in your machine, and if they are also creating problem then by this process they will also regain into their original; insert windows installation disk and start pressing f8 after the your machine manufacturer logo will appear into the screen. now you will proceed into the installation window, click on install now option, and select the drive, where the existing operating system is installed, it will format that drive first and then will load the OS in a fresh way. After that install the application or the software those are required for you.

I think the problems are occurring in your machine for the anti malwarebyte programs, for that I recommend you to simply run the windows default malwarebyte program , and start the scan process, wait till the process completes, and remove the malwarebytes those are gathered by the scanning process. Reboot your laptop, and see whether the problems are still occurring in your machine or not, if yes, then I recommend you to download TDSSKiller from HERE. This is a kaspersky production. Download and install this one, now scan the machine by this toll program. I hope by this the problems are surely solved

According to the browser freezing problem, I think the problem can be solved by reload the browser application. First of all remove the existing installed program, and along with this also remove the other files those are collaborating with the windows log file, and also remove the browser contained files from temporary folder and windows registry directory now start the re-installation process. I was also facing similar issue, after that I tried this problem is solved. And for the instances those are running in the background of your machine, go to the start up program list of your machine and from ether disable them those are needed to urn during the windows start up.

If you are using any original version of antivirus program, then I recommend you to scan your machine with that antivirus, be sure that the database file is up to dated. Along with this the other features like, anti malware, anti root kit etc, run them also. Wait till the processes are completes there process, reboot is might be required after that; I hope this time the problem will be solved. But still if you are having similar issue, then go for the online help of the antivirus developers. For that disable the windows security option, and along with this also disable the firewall option. Now from the antivirus user interface window, select the scan with online help option, click on it and wait for the response from the other side. Follow the instructions and the procedures.