Seem to have picked up a virus on my work computer, it won't let me run AVG . Anyone know of any free software that I might try to get rid of virus ?

i use avast ... it is free

Ditto the Avast. It walks the walk and talks.

We use AVG and malware bytes, it works for 95 percent of the issues I encounter. For really hosed systems I use combofix.

If I suspect a virus the first thing I do is boot into safe mode and then scan with one of these.

1. ESET Online Scanner

2. https://www.clamwin.com/- the portable version is super handy on a system that won't let you search the web.

Followed by one of these in safe mode.
1. Malwarebytes
2. Super Antispyware

Once you have cleaned the virus, use a good antivirus and pay for it. I wouldn't trust a free version on a system I REALLY needed. This is one of the best I've used. https://www.eset.com/us/

It freezes up when I try to boot in safe mode

Beg, borrow or steal a copy of Linux (Puppy Linux or Ubuntu). See if you can boot with that.
It will tell you if you have a hardware or software failure and you might be able to start repairing the hard drive from the Linux OS.

Carl

Kaspersky emergency repair is an ISO that one would burn to a CD. Boot the computer from the CD. Let the software run until complete. It will find the malware and remove it. The Kaspersky solution is Linux and, therefore, is not recognized by the malware so the system will boot. Be patient. It takes as long as it takes, sometimes hours, for the complete scan to run.

https://support.kaspersky.com/viruses

Rcaman

Not a fan of Kaspersky, but I do like ESET's online thing. I'm also very fond of the online scanner than Trend Micro provides. You might want to run your machine by both of them.

Pull the hard drive and connect it to another PC and run your scans from there.

Use and IDE/SATA to USB adapter to connect the hard drive to another PC.

One nice place to go is bleepingcomputer.com it's packed full of info on virus protection and removal..Good place to start.

...bob...

I'll also suggest to use avast is better then other.

Agreed, Bob.

Here's my recipe:

1) run Rkill to stop the active infection - get the renamed 'iexplorer.exe' version, usually slips by the nastiest ones..
2) run Combofix, reboot
3) run Norton Power Eraser, remove everything it finds (including Combofix if you want)
4) run Malwarebytes on full scan, remove everything it finds
5) enjoy

TDSSkiller is also handy for specific infections but usually the above will fix just about anything.

I don't like AVG, Avast or Avira simply because they've turned into bloatware over the years. These days I uninstall everything and then install M$ Security Essentials. It's free even for commercial use and works at least as well as the others. Norton and McAfee may have been pioneers but their names have been sold long ago and will only make matters worse (NPE being the exception!).